Chemical Vapor Deposition (CVD) Reactor

Abstract

The present invention relates to a CVD reactor, particularly a spout flow reactor, for preparing particulate materials. The present invention also relates to a method for preparing such materials using a CVD reactor, particularly a spout flow reactor. The present invention further relates to an electrode material, an electrode, and an alkali metal ion battery comprising the particulate material.

Description

[Technical Field]

[0001] Related Applications This application claims priority to Australian Provisional Patent Application No. AU2023 / 900088, filed January 16, 2023, which is incorporated by reference in its entirety.

[0002] The present invention relates to CVD reactors, particularly spout flow reactors. In particular, the present invention relates to spout flow reactors for preparing particulate materials, although it will be understood that the present invention is not limited to these particular fields of use. [Background technology]

[0003] The following description of the prior art is provided to place the present invention in its appropriate technical context and to enable a more complete understanding of its advantages, although it should be understood that any discussion of prior art throughout this specification should in no way be taken as a representation or admission that such prior art is widely known or forms part of the common general knowledge in the art.

[0004] Particulate materials are widely used in industrial applications. For example, carbonaceous particulate materials, including graphite powder, carbon black, and coke, can be used as electrode materials in alkali metal-ion batteries because they offer advantages such as low operating potential, higher conductivity, longer cycle life, and relatively low cost. Other particulate materials for such batteries include metallic lithium, lithium and silicon titanate, and / or their carbonaceous composites.

[0005] However, the use of particulate materials such as graphite has limitations. First, during the battery manufacturing process, a portion of the alkali metal forms a stable solid electrolyte interface on the graphite surface, resulting in only approximately 80% to 93% coulombic efficiency and permanent capacity loss for the battery during the first charge / discharge cycle. To address this issue, graphite with a low surface area is typically preferred due to a lower extent of electrolyte decomposition reactions. Second, graphite generally has poor rate performance, especially at low temperatures where alkali metal deposition can occur. To address this issue, the graphite particle size must be reduced to facilitate the diffusion of solid alkali metal, which results in higher delivery capacity at high rates. However, this inevitably involves using graphite with a larger surface area, which leads to the capacity loss discussed above. Other factors, including particle morphology, electrode thickness, porosity, binder selection, and electrolyte composition, affect the rate capability of graphite-based electrode materials.

[0006] Silicon is considered a promising alternative electrode material, however, it generally suffers from huge volume changes (on the order of 300%) during the lithiation and delithiation processes, which causes cracking and shattering of the active material and subsequent disintegration of the electrode, leading to rapid degradation of capacity.

[0007] It has been suggested that the surface of particulate materials can be modified via polymer, metal, or carbon coatings to overcome some of the above problems. For example, isotropic amorphous carbon has been reported to allow random lithium ion intercalation, which may lead to improved rate capacity in batteries with carbon-coated graphite electrodes. Furthermore, improved cycling performance has been observed in batteries with carbon-coated graphite electrodes in electrolytes containing propylene carbonate. Furthermore, carbon-coated silicon particles have been shown to improve the performance of alkali-ion batteries.

[0008] PCT Application WO 2015 / 197005 discloses a method for modifying carbon nanotubes using cyclopentadiene. In some embodiments, the carbon nanotubes are fluidized and the reaction is carried out in a tubular reactor.

[0009] PCT Application WO 2016 / 135328 discloses surface-modified carbonaceous materials having nanoparticles attached to the surface of the material, and processes for preparing such carbonaceous materials. In one embodiment, carbonaceous particles are surface-modified by depositing nanoparticles on the surface in a plasma reactor. For example, nanoparticles are attached to the surface of the carbonaceous particles by plasma-enhanced chemical vapor deposition in the presence of a hydrocarbon. In some embodiments, the residence time of the particles is in the range of 0.05 to 0.5 seconds.

[0010] PCT Application WO 2016 / 008951 discloses surface-modified carbonaceous particulate materials having a hydrophilic non-graphitic carbon coating. In some embodiments, the coating process is carried out in a fluidized bed reactor using a chemical vapor deposition process.

[0011] Korean Patent Application No. 101776246 discloses a negative electrode active material for lithium secondary batteries, specifically a material that exhibits high capacity in the form of a structure in which multiple nanostructures are aggregated, where at least a portion of the structure is bonded to a carbon-based support to form a composite material, and a carbon coating layer is located on the surface of the structure and / or the carbon-based support. The deposition process is carried out in an unspecified reactor in the presence of a hydrocarbon gas.

[0012] Han and Lee ("Improvement on the electrochemical characteristics of graphite anode by coating of the pyrolytic carbon using tumbling chemical vapor deposition," Electrochimica Acta, Vol. 48, Issue 8, pp. 1073-1079) disclose graphite coated with pyrolytic carbon using tumbling chemical vapor deposition.

[0013] Other representative prior art includes, but is not limited to, CN112755994, WO2016 / 045937, CN113751003, CN105600784, WO2012 / 048185, WO0012447, WO2020 / 073101, JP2004 / 244690, US7,750,194, US5,431,968, and US8,980,195.

[0014] In order to modify the surface of the particulate material, it is preferable that the particulate material be uniformly fluidized before modification. A wide particle size distribution is preferable to achieve good fluidization behavior. In the case of coarser particles, this can result in uneven deposition of the coating material on the particles. Furthermore, when fluidized, finer particles tend to leave the reactor without or with partial surface modification because the residence time of the finer particles is shorter compared to the residence time of the coarser particles.

[0015] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0016] It is an object of particularly preferred forms of the present invention to provide new or improved CVD reactors, particularly entrained flow reactors, for preparing surface-modified particulate materials, methods for preparing such materials, electrode materials and / or electrodes comprising such materials, and / or alkali metal ion batteries.

[0017] Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprise," "comprising," and the like are to be construed in an inclusive sense, i.e., "including, but not limited to," rather than in an exclusive or exhaustive sense.

[0018] Although the present invention will be described with reference to specific examples, those skilled in the art will appreciate that the present invention can be embodied in many other forms. Summary of the Invention

[0019] According to a first aspect of the present invention, there is provided a CVD reactor for preparing a particulate material, the reactor comprising: a first inlet conduit; a first bend having one end located at the end of the first inlet conduit and another end located at the beginning of the first outlet conduit; The particulate material is prepared by flowing the feedstock through inlet and outlet conduits while contacting it with a hydrocarbon gas mixed with an inert gas at a temperature of about 500°C to about 1500°C.

[0020] In some embodiments, the CVD reactor is a jet flow reactor.

[0021] Advantageously, the present inventors have developed a CVD reactor, particularly a spout-flow reactor, for preparing particulate materials, including those with finer particle sizes and / or dense / narrow particle size distributions. This is accomplished by flowing the particulate material through a serpentine / sinusoidal path, including an inlet conduit, bends, and an outlet conduit, as described above, so that the particulate material, particularly those with finer particle sizes, has sufficient time to react with the hydrocarbon gas as it travels through the serpentine / sinusoidal path. Because of the limited potential for backmixing of materials, the reactor approaches the theoretical plug flow regime. Those skilled in the art will appreciate that a plug flow reactor provides good continuous solids residence time control. Continuous feed and discharge allow for good steady-state control.

[0022] In another aspect, the present invention relates to a CVD reactor for or when used to prepare a particulate material, the reactor comprising: a first inlet conduit; a first bend having one end located at the end of the first inlet conduit and another end located at the beginning of the first outlet conduit; The particulate material is prepared by flowing the feedstock through inlet and outlet conduits while contacting it with a hydrocarbon gas mixed with an inert gas at a temperature of about 500°C to about 1500°C.

[0023] In one embodiment, the particulate material is a surface-modified particulate material.

[0024] In one embodiment of the present invention, the reactor is preferably aligned vertically, which further ensures that particles of all sizes move at the same average velocity relative to the gas phase (i.e., larger particles may rise slower but fall faster, so that the average residence time for all particles is similar after completing one loop).

[0025] Residence time Those skilled in the art will understand that as the size (and weight) of a particulate material decreases, its residence time within the reactor decreases accordingly. In other words, materials with finer particle sizes may not have enough time to come into contact with the hydrocarbon gas, potentially causing an incomplete / partial reaction. To overcome this problem, reactors are designed to ensure a residence time for the particulate material so that the material has a sufficient volume to react with the hydrocarbon gas.

[0026] In one embodiment of the present invention, the feedstock has a residence time in the reactor of from about 4 minutes to about 100 minutes. For example, the residence time is about 4 to 5 minutes, or about 5 to 6 minutes, or about 6 to 7 minutes, or about 7 to 8 minutes, or about 8 to 9 minutes, or about 9 to 10 minutes, or about 10 to 15 minutes, or about 15 to 20 minutes, or about 20 to 25 minutes, or about 25 to 30 minutes, or about 30 to 35 minutes, or about 35 to 40 minutes, or about 40 to 45 minutes, or about 45 to 50 minutes, or about 50 to 55 minutes, or about 55 to 60 minutes, or about 60 to 65 minutes, or about 65 to 70 minutes, or about 70 to 75 minutes, or about 75 to 80 minutes, or about 80 to 85 minutes, or about 85 to 90 minutes, or about 90 to 95 minutes, or about 95 to 100 minutes.

[0027] In a preferred embodiment of the present invention, the residence time is about 15 to 45 minutes. In a particularly preferred embodiment of the present invention, the residence time of the particulate material is about 15 minutes.

[0028] In another embodiment of the invention, the residence time is about 4 minutes.

[0029] In some embodiments of the present invention, all of the particulate materials have substantially the same residence time in the reactor.

[0030] supply material In one embodiment of the invention, the feed material is selected from the group consisting of carbonaceous particulate materials, metallic lithium, lithium titanate, tin-based alloys, silicon-carbon-based materials, and silicon-based materials such as silicon particles coated with a carbonaceous material, preferably graphite-coated silicon nanoparticles or carbon-coated silicon nanoparticles. In some embodiments of the invention, the carbonaceous material is selected from the group consisting of natural graphite, synthetic graphite, exfoliated graphite, amorphous graphite, carbon black, coke, graphene, graphene fibers, graphene nanotubes, coal tar pitch, PVA, and carbon-containing polymers.

[0031] In one embodiment of the present invention, the feed material is silicon, preferably micrometer-sized silicon, more preferably silicon having a size between 0.4 and 20 micrometers.

[0032] In one embodiment of the present invention, the feed material comprises a cathode material. In one embodiment, the cathode material is selected from one or more of the group including LFP (lithium iron phosphate), LFPM (lithium iron manganese phosphate), LNMO (lithium nickel manganese oxide), LMO (lithium manganese oxide), LiNiCoMn (NCM), LiCoO (LCO), NCA (nickel cobalt alumina), LiTiOMn, NMA (LiNiMnAlO), and LiNbMn. In one embodiment, the cathode material is comprised of a mixture of cathode materials. As will be understood by those skilled in the art, other cathode materials may be used as the particulate material of the present invention, and such materials are within the scope of the present invention.

[0033] In some embodiments, the cathode material comprises a single crystal nickel-based cathode material, preferably NCM or NCA.

[0034] In some embodiments, the cathode material comprises a lithium-excess disordered rock salt cathode (DRX).

[0035] In some embodiments, the cathode material comprises a quaternary transition metal oxide layered framework, preferably NCMA (LiNiCoMnAlO 2 ).

[0036] In some embodiments, the cathode material comprises a sulfur-based cathode material, for example, one suitable for use in a Li-S battery.

[0037] In some embodiments, the cathode material is a doped cathode material.

[0038] In some embodiments, the doped cathode material comprises any one element or combination of two or more elements from the list including: Mg, Co, Al, Ni, Nb, Fe, Mn, Mo, V, Ti, Cr, Al, P, B, Zr, Ru, F, S, Na, Nd, Cu, Bi, Y, Pd, Pt, Ta, Ga, or Si.

[0039] In some embodiments of the present invention, the feed material comprises silicon particles. Preferably, the silicon particles have a size ranging from about 10 nm to 400 nm, more preferably from about 50 nm to 300 nm. For example, the silicon particles have a size of about 10 nm to about 20 nm, or about 20 nm to 30 nm, or about 30 nm to 40 nm, or about 40 nm to 50 nm, or about 50 nm to 60 nm, or about 60 nm to 70 nm, or about 70 nm to 80 nm, or about 80 nm to 90 nm, or about 90 nm to 100 nm, or about 100 nm to 110 nm, or about 110 nm to 150 nm, or about 150 nm to 200 nm, or about 200 nm to 250 nm, or about 250 nm to 300 nm, or about 300 nm to 350 nm, or about 350 nm to 400 nm. In particularly preferred embodiments of the present invention, the silicon particles have a size of about 100 nm. In some embodiments of the present invention, size refers to the diameter of the particle.

[0040] In some embodiments of the present invention, the carbonaceous particulate material is selected from the group consisting of natural graphite, synthetic graphite, exfoliated graphite, amorphous graphite, amorphous carbon, carbon black, coke, graphene, graphene fibers, and graphene nanotubes. In some embodiments, the carbonaceous particulate material at least substantially encapsulates or surrounds a secondary material. In some embodiments, the secondary material is selected from the group comprising lithium metal, lithium titanate, tin-based alloys, and silicon-based materials, preferably silicon particles, preferably silicon nanoparticles.

[0041] In one embodiment of the present invention, the feed material has a size of about 0.001 μm to about 1000 μm. For example, the feed material may be about 0.001 μm to about 0.005 μm, or about 0.005 μm to about 0.01 μm, or about 0.01 μm to about 0.05 μm, or about 0.05 μm to about 0.1 μm, or about 0.1 μm to about 0.2 μm, or about 0.2 μm to about 0.3 μm, or about 0.3 μm to about 0.4 μm, or about 0.4 μm to about 0.5 μm, or about 0.5 μm to about 0.6 μm, or about 0.6 μm to about 0.7 μm, or about 0.7 μm to about 0.8 μm, or about 0. 8 μm to about 0.9 μm, or about 0.9 μm to about 1 μm, or about 1 μm to about 5 μm, or about 5 μm to about 10 μm, or about 10 μm to about 15 μm, or about 15 μm to about 20 μm, or about 20 μm to about 25 μm, or about 25 μm to about 30 μm, or about 30 μm to about 35 μm, or about 35 μm to about 40 μm, or about 40 μm to about 45 μm, or about 45 μm to about 50 μm, or about 50 μm to about 55 μm, or about 55 μm to about 60 μm, or about 60 μm to about 6 5 μm, or about 65 μm to about 70 μm, or about 70 μm to about 75 μm, or about 75 μm to about 80 μm, or about 80 μm to about 85 μm, or about 85 μm to about 90 μm, or about 90 μm to about 95 μm, or about 95 μm to about 100 μm, or about 100 μm to about 150 μm, or about 150 μm to about 200 μm, or about 200 μm to about 250 μm, or about 250 μm to about 300 μm, or about 300 μm to about 350 μm, or about 350 μm to about 400 μm, or has a size of about 400 μm to about 450 μm, or about 450 μm to about 500 μm, or about 500 μm to about 550 μm, or about 550 μm to about 600 μm, or about 600 μm to about 650 μm, or about 650 μm to about 700 μm, or about 700 μm to about 750 μm, or about 750 μm to about 800 μm, or about 800 μm to about 850 μm, or about 850 μm to about 900 μm, or about 900 μm to about 950 μm, or about 950 μm to about 1000 μm.

[0042] In another embodiment of the invention, the feed material has a particle size distribution D50 of about 5 μm to 25 μm, for example, the particle size distribution D50 is 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, or 25 μm.

[0043] reactor In some embodiments of the invention, the reactor further comprises n bends, each bend having an n+1 inlet conduit and an n+1 outlet conduit, the n outlet conduit being in fluid communication with the n+1 inlet conduit and defining the n+1 inlet conduit. In particular embodiments of the invention, the reactor further comprises a second bend having a second inlet conduit and a second outlet conduit, the first outlet conduit being in fluid communication with the second inlet conduit and defining the second inlet conduit.

[0044] For example, the reactor may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 bends, which have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inlet and outlet conduits, where the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, first The first, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, or nineteenth outlet conduit is in fluid communication with and defines the second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, nineteenth, or twentieth conduit, respectively. In other embodiments of the invention, the reactor comprises more than 20 bends.

[0045] Those skilled in the art will appreciate that the reactor comprises a serpentine, sinusoidal, or "wave" path for the particulate material to flow through while in contact with the hydrocarbon gas. Advantageously, this increases the residence time of the particulate material within the reactor so that the particulate material has sufficient time to react with the hydrocarbon gas, resulting in complete surface modification.

[0046] In some embodiments, the bend is angled between about 0° and about 180°, or between about 30° and about 150°, or between about 60° and about 120°. For example, the bend can be angled at about 0° to about 10°, about 10° to about 20°, about 20° to about 30°, about 30° to about 40°, about 40° to about 50°, about 50° to about 60°, about 60° to about 70°, about 70° to about 80°, about 80° to about 90°, about 90° to about 100°, about 100° to about 110°, about 110° to about 120°, about 120° to about 130°, about 130° to about 140°, about 140° to about 150°, about 150° to about 160°, about 160° to about 170°, or about 170° to about 180°. The bend may be angled at about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, or 180 degrees.

[0047] In preferred embodiments, the bend is angled at about 45°, about 90°, or about 135°.

[0048] In one embodiment of the present invention, the bend is semicircular.

[0049] In one embodiment of the invention, each respective conduit is circular in cross section. In some embodiments of the invention, each respective conduit is of the same cross-sectional area. In some embodiments of the invention, each respective conduit is of a different cross-sectional area. Preferably, the diameter of the conduit can be varied to maintain a constant jet velocity along the path of the reactor with increasing gas flow. In certain embodiments, the conduit diameter increases from the conduit inlet to the conduit outlet.

[0050] In some embodiments, the inlet and / or outlet conduits are fitted with cleaning ports which may advantageously provide periodic "bumping" with additional inert gas, e.g., argon gas, to move any large particles that have accumulated onward.

[0051] In some embodiments of the present invention, the total length of the conduit is from about 10 m to about 300 m. For example, the length is about 10 m to about 20 m, or about 20 m to about 30 m, or about 30 m to about 40 m, or about 40 m to about 50 m, or about 50 m to about 60 m, or about 60 m to about 70 m, or about 70 m to about 80 m, or about 80 m to about 90 m, or about 90 m to about 100 m, or about 100 m to about 120 m, or about 120 m to about 140 m, or about 140 m to about 160 m, or about 160 m to about 180 m, or about 180 m to about 200 m, or about 200 m to about 220 m, or about 220 m to about 240 m, or about 240 m to about 260 m, or about 260 m to about 280 m, or about 280 m to about 300 m. In one embodiment of the invention, the total length of the conduit is about 36 m. In another embodiment, the total length is about 180 m.

[0052] inert gas Those skilled in the art will appreciate that the use of flowing inert gas avoids oxidation of the feed materials, particularly the carbonaceous particulate material.

[0053] In one embodiment of the present invention, the inert gas is helium, nitrogen, argon, or neon, or a combination thereof. In a preferred embodiment of the present invention, the inert gas is argon.

[0054] In one embodiment of the present invention, the inert gas is introduced into the reactor at multiple points along the inlet and / or outlet conduits, each point preferably being capable of operating independently of the other in terms of flow rate and / or pressure and / or type of inert gas.

[0055] In one embodiment of the invention, the hydrocarbon gas is introduced into the reactor at multiple points along the inlet and / or outlet conduits, each point preferably being operable independently of the other in terms of flow rate and / or pressure and / or type of hydrocarbon gas.

[0056] In one embodiment of the present invention, the hydrocarbon gas and the inert gas are introduced into the reactor at multiple points along the inlet and / or outlet conduits. In one embodiment, the inert gas provides a constant gas flow along the reactor, and the hydrocarbon gas is inserted at multiple points along the inlet and / or outlet conduits.

[0057] In some embodiments, the reactor comprises one or more inert gas inlets, preferably two or more inert gas inlets, along the inlet and / or outlet conduits for introducing inert gas into the reactor. For example, the reactor may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inert gas inlets.

[0058] In one embodiment, the hydrocarbon gas or carrier gas can be preheated to a temperature within at least about 1-50%, preferably 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, or 45%, of the temperature in the reactor.

[0059] Temperature and Pressure Those skilled in the art will appreciate that the reaction temperature and / or pressure will depend on the particular feedstock and / or hydrocarbon gas.

[0060] The feedstock is contacted with the hydrocarbon gas at a temperature of about 500° C. to about 1500° C. For example, the temperature may be about 500° C. to about 550° C., or about 550° C. to about 600° C., or about 600° C. to about 650° C., or about 650° C. to about 700° C., or about 700° C. to about 750° C., or about 750° C. to about 800° C., or about 800° C. to about 850° C., or about 850° C. to about 900° C., or about 900° C. to about 950° C., or about 950° C. to about 1000° C., or about 1000° C. °C to about 1050°C, or about 1050°C to about 1100°C, or about 1100°C to about 1150°C, or about 1150°C to about 1200°C, or about 1200°C to about 1250°C, or about 1250°C to about 1300°C, or about 1300°C to about 1350°C, or about 1350°C to about 1400°C, or about 1400°C to about 1450°C, or about 1450°C to about 1500°C.

[0061] In one embodiment of the present invention, the feedstock is contacted with the hydrocarbon gas at a temperature of about 600° C. to about 1200° C. In a preferred embodiment of the present invention, the feedstock is contacted with the hydrocarbon gas at a temperature of about 1000° C.

[0062] In one embodiment of the present invention, the feedstock is contacted with the hydrocarbon gas at a pressure of about 25 kPag to about 75 kPag. For example, the pressure is about 25 kPag to about 30 kPag, or about 30 kPag to about 35 kPag, or about 35 kPag to about 40 kPag, or about 40 kPag to about 45 kPag, or about 45 kPag to about 50 kPag, or about 50 kPag to about 55 kPag, or about 55 kPag to about 60 kPag, or about 60 kPag to about 65 kPag, or about 65 kPag to about 70 kPag, or about 70 kPag to about 75 kPag. In a preferred embodiment of the present invention, the feedstock is contacted with the hydrocarbon gas at a pressure of 50 kPag.

[0063] hydrocarbon gas Preferably, surface modification of the feed material is accomplished by contacting the material to be modified with a hydrocarbon gas.

[0064] In one embodiment of the present invention, the hydrocarbon gas is an aliphatic or aromatic hydrocarbon, optionally containing one or more nitrogen atoms, and is selected from the group consisting of methane, ethane, ethylene, propane, propene, acetylene, butane, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, acetonitrile, pyrrole, quinoline, isoquinoline, acridine, pyrazine, quinoxaline, imidazole, benzimidazole, purine, pyrazole, indazole, pyrimidine, quinazoline, pyridazine, cinnoline, pyridine, dimethylformamide (DMF), nitromethane, benzene, toluene, xylene, and combinations thereof, preferably methane or short-chain hydrocarbons. In one embodiment, the hydrocarbon gas is natural gas or is sourced from biogas.

[0065] In a particular embodiment of the present invention, the hydrocarbon gas is propane.

[0066] In some embodiments, the hydrocarbon gas further comprises a secondary gas.

[0067] In some embodiments, the secondary gas is a nitrogen-containing gas, preferably acetonitrile or pyrrole.

[0068] In some embodiments, the hydrocarbon gas further comprises a dopant, preferably the dopant is nitrogen or alumina.

[0069] In one embodiment of the present invention, hydrocarbon gas is introduced into the reactor at multiple points along the inlet and / or outlet conduits. Preferably, each point can operate independently of the other with respect to flow rate and / or pressure and / or type of hydrocarbon gas. In one embodiment of the present invention, the reactor gas is analyzed in tandem at multiple points to allow determination of steady-state equilibrium and control of the reactive gas input rate and / or position along the path with respect to residence time.

[0070] Advantageously, introducing the hydrocarbon gas into the reactor at multiple points along the inlet and / or outlet conduits provides flexibility in controlling particle residence time, reaction rate, and / or product uniformity. In this way, the reactor and / or process can be designed so that all particles have similar residence times in the reactor and uniform reaction occurs on all particles.

[0071] In some embodiments, the hydrocarbon gas is introduced into the reactor at multiple points along the inlet and / or outlet conduits via multiple "cold" nozzles (external to the heating means). Advantageously, this reduces the risk of blockage due to carbon deposition.

[0072] In some embodiments, the reactor is equipped with a sampling means for sampling the exhaust gas stream at intermediate stages in a progressive manner to ascertain the extent of reaction.

[0073] Liquidation In one embodiment of the present invention, the reactor is equipped with a feed control system for feeding the feed material to the reactor.

[0074] In some embodiments of the present invention, the feed control system comprises a compartment in which the feed material is fluidized by a supply of carrier gas and introduced into the reactor.

[0075] When a gas stream is introduced through the bottom of a bed of solid particles, it moves upward through the bed via the empty spaces between the particles. At low gas velocities, the aerodynamic drag on each particle is also low, so the bed remains stationary. As the velocity increases, the aerodynamic drag begins to counteract gravity, expanding the volume of the bed as the particles move away from each other. Further increases in velocity reach a critical value where the upward drag force just equals the downward gravity force and the fine particles become suspended in the fluid. At this critical value, the bed is said to be fluidized and exhibits fluid behavior. Further increases in gas velocity continue to decrease the bulk density of the bed, and the fluidization becomes stronger until the particles no longer form a layer and are "entrained" upward by the gas flow.

[0076] In some embodiments of the present invention, the carrier gas is an inert gas as described above. In some embodiments of the present invention, the carrier gas comprises helium, nitrogen, argon, or neon, or a combination thereof. In one embodiment, the carrier gas further comprises about 1% to 10% v / v hydrogen, preferably as a reducing agent, e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% v / v. Preferably, the carrier gas further comprises 5% v / v hydrogen.

[0077] In some embodiments of the present invention, the carrier gas is at a concentration of about 0.01 sm 3 / h~0.1sm 3 / h, e.g., 0.01sm 3 / h, 0.02sm 3 / h, 0.03sm 3 / h, 0.04sm 3 / h, 0.05sm 3 / h, 0.06sm 3 / h, 0.07sm 3 / h, 0.08sm 3 / h, 0.09sm 3 / h, or 0.1sm 3 In one embodiment of the present invention, the carrier gas has a flow rate of about 0.04 sm 3In another embodiment of the present invention, the carrier gas has a flow rate of about 0.05 sm 3 In another embodiment, the carrier gas flow rate is 0.1 sm / h. 3 / h. Those skilled in the art will appreciate that the flow rate of the carrier gas depends on many factors, including the flow rate of the feed material, the diameter of the conduit, and the length of the conduit.

[0078] In one embodiment of the invention, the flow of the fluidized feed material is characterized as turbulent. Advantageously, this results in tumbling of the feed material within the reactor and surface modification by uniform coating or deposition. In another embodiment of the invention, the flow of the fluidized feed material is characterized as laminar.

[0079] In one embodiment of the present invention, carrier gas is introduced into the reactor at multiple points along the inlet and / or outlet conduits. Preferably, each point can be operated independently of the other with respect to flow rate and / or pressure, and / or type of carrier gas. Advantageously, this maintains the feed material in a fluidized state, and carrier gas pressure and / or flow rate can be varied to increase particle weight as the particles progress through the reactor. In addition, it should be recognized that the reactor pipe diameter can be adjusted by design to maintain a relatively constant fluidization velocity as the gas input along the reactor path increases.

[0080] In some embodiments of the present invention, the carrier gas can be preheated. In a preferred embodiment of the present invention, the carrier gas is preheated by receiving heat from the particulate material and spent carrier gas in a heat exchanger, for example, a pipe-in-pipe heat exchanger. Advantageously, this increases the temperature of the fluidized feed stream, reducing the heat required for the reaction and thereby increasing the energy efficiency of the process.

[0081] In one embodiment of the present invention, the feed material is fed in batches. Preferably, the feed material is fed in batches using a lock hopper (single, double, and / or other). Those skilled in the art will appreciate that a lock hopper provides a means to both allow operation of many feeders with only low-pressure capability to operate at very high pressures, and allow continuous transfer from a single blow tank feeder. The lock hopper is positioned between the feed hopper, which is typically at atmospheric pressure to allow continuous loading of material, and the material feeder, which can be at any pressure required, almost without limit.

[0082] In other embodiments of the invention, the feed material is fed continuously. In other embodiments of the invention, the feed material is fed in batches. In some embodiments, the feed material is fed in batches at different locations within the conduit. In other embodiments of the invention, the feed material is fed continuously at different locations within the conduit.

[0083] In some embodiments, the feed control system comprises an agitating screw feeder.

[0084] In some embodiments of the invention, the feedstock is fed at a rate of about 0.1 kg / h to about 10 kg / h, e.g., 2 kg / h, 3 kg / h, 4 kg / h, 5 kg / h, 6 kg / h, 7 kg / h, 8 kg / h, 9 kg / h, or 10 kg / h. In certain embodiments of the invention, the feedstock is fed at about 5 kg / h. In other embodiments, the feedstock is fed at a rate greater than 10 kg / h. For example, the speed may be 20 kg / h, 50 kg / h, 100 kg / h, 200 kg / h, 300 kg / h, 400 kg / h, 500 kg / h, 600 kg / h, 700 kg / h, 800 kg / h, 900 kg / h, 1000 kg / h, 2000 kg / h, 3000 kg / h, 4000 kg / h, 5000 kg / h, 6000 kg / h, 7000 kg / h, 8000 kg / h, 9000 kg / h, 10000 kg / h.

[0085] In some embodiments of the invention, the feedstock has a volume fraction of about 1% to about 10% in the fluidized feed stream, e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. In one embodiment of the invention, the volume fraction is about 2%.

[0086] In some embodiments of the present invention, the feedstock has a Geldart classification of A or C.

[0087] In some embodiments of the present invention, the fluidized feedstock has a flow rate of about 1 kg / m 2 s~10kg / m 2 s, e.g., 1 kg / m 2 s, 2 kg / m 2 s, 3 kg / m 2 s, 4 kg / m 2 s, 5 kg / m 2 s, 6 kg / m 2 s, 7 kg / m 2 s, 8 kg / m 2 s, 9 kg / m 2 s, 10 kg / m 2 In one embodiment of the present invention, the solids flux is about 7 kg / m 2 It is s.

[0088] In some embodiments of the present invention, the fluidized feedstock has a velocity within the reactor of about 0.1 m / s to 1 m / s. For example, the velocity is about 0.1 m / s to 0.2 m / s, or about 0.2 m / s to 0.3 m / s, or about 0.3 m / s to 0.4 m / s, or about 0.4 m / s to 0.5 m / s, or about 0.5 m / s to 0.6 m / s, or about 0.6 m / s to 0.7 m / s, or about 0.7 m / s to 0.8 m / s, or about 0.8 m / s to 0.9 m / s, or about 0.9 m / s to 1 m / s. In one embodiment of the present invention, the fluidized feedstock has a velocity of about 0.15 m / s. In another embodiment of the present invention, the velocity is about 0.2 m / s.

[0089] heating means In a preferred embodiment of the present invention, the reactor further comprises a heating means for heating the reactor.

[0090] In one embodiment of the invention, the heating means comprises a burner for burning a mixture of gaseous fuel, for example natural gas or liquefied petroleum gas, and air, preferably low pressure air.

[0091] In another embodiment of the invention, the heating means comprises an oven or a heating element, for example an electrical resistance.

[0092] In other embodiments of the invention, the heating means comprises an electrically heated furnace. In a particular embodiment of the invention, the reactor is located in a split electrically heated muffle furnace.

[0093] Separation means In one embodiment of the present invention, the reactor further comprises a separation means in fluid communication with the outlet conduit for separating the particulate material from the gas. Those skilled in the art will understand that the feed stream, e.g., the fluidized feed stream at the end of the outlet conduit, can comprise a mixture of particulate material and / or hydrocarbon gas and a carrier gas. After separation, the particulates can be collected and stored in a storage unit, such as a metal drum.

[0094] Advantageously, once the mixture is cooled, there is no intermediate hot gas-solids separation stage within the reactor other than the outlet conduit.

[0095] In a preferred embodiment of the present invention, the separating means comprises a sintered metal filter. Those skilled in the art will appreciate that sintered metal filters are used for hot gas filtration. These filters can provide high particulate capture efficiencies. In one embodiment of the present invention, the capture efficiency is up to 90%. In other embodiments of the present invention, the capture efficiency is from about 90% to about 99.99%. In a particularly preferred embodiment of the present invention, the capture efficiency is about 99.9%.

[0096] In some embodiments, the separating means comprises a cyclone having a separation efficiency of 80 to 99.99%.

[0097] In another embodiment, the separating means comprises a bag filter having a separation efficiency of 80-99.99%. The bag filter can be made of PTFE, sintered metal, or other components.

[0098] In one embodiment of the present invention, the sintered metal filter is insulated. Sintered metal filters may require insulation if dew point problems occur. Those skilled in the art will understand that dew point is the temperature at which components in a mixed gas begin to condense. For example, during a filtration process, when a feed stream, e.g., a fluidized feed stream, is mixed with a cooling gas at the outlet, hydrocarbon gases may condense at a certain pressure and / or temperature, depending on the composition and / or type of hydrocarbon gas. This always poses challenges in gas-solid particle separation in sintered metal filters and must be avoided.

[0099] In one embodiment of the present invention, the separating means comprises a plurality of sintered metal filters arranged in series, in parallel, or in a series-parallel combination.

[0100] In one embodiment of the present invention, the separation means comprises a back-pulsing, fast acting valve to prevent clogging of the filter membrane pores.

[0101] In a preferred embodiment of the present invention, the separated gas is recycled back to the reactor. Advantageously, this saves material costs and increases reactor utilization efficiency. In one embodiment, the separated gas is compressed before recycling it to the reactor.

[0102] According to a second aspect of the present invention, there is provided a method of preparing a particulate material, the method comprising flowing a feed material through a CVD reactor, the CVD reactor comprising: a first inlet conduit; a first bend having one end located at the end of the first inlet conduit and another end located at the beginning of the first outlet conduit; The particles flow through inlet and outlet conduits while in contact with hydrocarbon gas at temperatures between about 500°C and about 1500°C under a flowing inert gas.

[0103] In one embodiment, the CVD reactor is a jet flow reactor.

[0104] In one embodiment of the present invention, the method further comprises recycling at least a portion of the particulate material back to the reactor.

[0105] In one embodiment of the present invention, the particulate material is a surface-modified particulate material, including graphite, micrometer-sized or nano-sized silicon, and silicon carbon composites.

[0106] According to a third aspect of the present invention there is provided a particulate material obtained or obtainable from a method according to the second aspect of the present invention.

[0107] In one embodiment of the present invention, the particulate material is a surface-modified particulate material.

[0108] In one embodiment of the present invention, the particulate material is silicon particles coated with at least one layer of carbonaceous material, preferably graphite-coated silicon nanoparticles or carbon-coated silicon nanoparticles, for example, the silicon particles are coated with 1, 2, 3, 4, or 5 layers of carbonaceous material.

[0109] In one embodiment of the present invention, the silicon particles are coated with a layer of carbonaceous material having a thickness of about 0.1 nm to about 100 nm, preferably about 5 nm to about 30 nm, and more preferably about 5 nm to about 20 nm. For example, the layer has a thickness of about 0.1 nm to about 0.2 nm, or about 0.2 nm to about 0.3 nm, or about 0.3 nm to about 0.4 nm, or about 0.4 nm to about 0.5 nm, or about 0.5 nm to about 0.6 nm, or about 0.6 nm to about 0.7 nm, or about 0.7 nm to about 0.8 nm, or about 0.8 nm to about 0.9 nm, or about 0.9 nm to about 1 nm, or about 1 nm to about 10 nm, or about 10 nm to about 20 nm, or about 20 nm to about 30 nm, or about 30 nm to about 40 nm, or about 40 nm to about 50 nm, or about 50 nm to about 60 nm, or about 60 nm to about 70 nm, or about 70 nm to about 80 nm, or about 80 nm to about 90 nm, or about 90 nm to about 100 nm. In another embodiment of the present invention, the layer has a thickness of about 0.025% to about 1000%, preferably about 1.25% to about 300%, and more preferably about 1.25% to about 200% of the particle size. For example, the thickness is about 0.025% to about 0.1%, or about 0.1% to about 1%, or about 1% to about 10%, or about 10% to about 100%, or about 100% to about 200%, or about 200% to about 300%, or about 300% to about 400%, or about 400% to about 500%, or about 500% to about 600%, or about 600% to about 700%, or about 700% to about 800%, or about 800% to about 900%, or about 900% to about 1000%.

[0110] In one embodiment of the present invention, silicon particles are coated with two layers of carbonaceous material. The layers have a thickness of about 0.1 nm to about 400 nm, preferably about 100 nm to about 300 nm, more preferably about 100 nm to about 250 nm, and particularly preferably about 100 nm to about 200 nm. For example, the layers may have a thickness of about 0.1 nm to about 0.2 nm, or about 0.2 nm to about 0.3 nm, or about 0.3 nm to about 0.4 nm, or about 0.4 nm to about 0.5 nm, or about 0.5 nm to about 0.6 nm, or about 0.6 nm to about 0.7 nm, or about 0.7 nm to about 0.8 nm, or about 0.8 nm to about 0.9 nm, or about 0.9 nm to about 1 nm, or about 1 nm to about 10 nm, or about 10 nm to about 20 nm. nm, or about 20 nm to about 30 nm, or about 30 nm to about 40 nm, or about 40 nm to about 50 nm, or about 50 nm to about 60 nm, or about 60 nm to about 70 nm, or about 70 nm to about 80 nm, or about 80 nm to about 90 nm, or about 90 nm to about 100 nm, or about 100 nm to about 200 nm, or about 200 nm to about 300 nm, or about 300 nm to about 400 nm. In another embodiment of the present invention, the layer has a thickness of about 0.025% to about 4000%, preferably about 25% to about 3000%, more preferably about 25% to about 2500%, and particularly preferably about 25% to about 2000% of the particle size. For example, the thickness is about 0.025% to about 0.1%, or about 0.1% to about 1%, or about 1% to about 10%, or about 10% to about 100%, or about 100% to about 200%, or about 200% to about 300%, or about 300% to about 400%, or about 400% to about 500%, or about 500% to about 600%, or about 600% to about 700%, or about 700% to about 800%, or about 800% to about 900%, or about 900% to about 1000%, or about 1000% to about 2000%, or about 2000% to about 3000%, or about 3000% to about 4000%.

[0111] In one embodiment of the present invention, the coated silicon particles comprise about 3% to about 20%, preferably about 5% to 15%, and more preferably about 5% to 10% carbonaceous material. For example, the silicon particles are coated with 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20% carbonaceous material, preferably graphite, amorphous carbon, and / or mixtures thereof.

[0112] In a preferred embodiment of the present invention, the coated silicon particles are in the form of clusters and / or agglomerates. Advantageously, clusters and / or agglomerates of coated silicon particles are easier to ship, handle, and / or manage.

[0113] In some embodiments of the present invention, the clusters and / or agglomerates of coated silicon particles have at least one of the following properties: D of approximately 1 μm to approximately 10 μm 10 Size distribution, D of approximately 5 μm to approximately 150 μm 50 Size distribution, D of approximately 10 μm to approximately 200 μm 90 Size distribution, and D of approximately 30 μm to approximately 300 μm 最大 Size distribution. In a preferred embodiment of the present invention, the clusters and / or agglomerates have a D of about 100 nm. 50 In another preferred embodiment of the present invention, the clusters and / or agglomerates have a size distribution of about 5 μm D 10 Size distribution, D of about 10 μm to about 12 μm 50 Size distribution, 25 μm D 90 Size distribution, and / or D of about 40 μm 最大 In another preferred embodiment of the present invention, the clusters and / or agglomerates have a size distribution of D less than about 40 μm. 最大 It has a size distribution.

[0114] According to a fourth aspect of the present invention there is provided the use of a particulate material according to the third aspect of the present invention for preparing an electrode material.

[0115] According to a fifth aspect of the present invention, there is provided an electrode material comprising a particulate material according to the third aspect of the present invention.

[0116] According to a sixth aspect of the present invention there is provided the use of an electrode material according to the fifth aspect of the present invention for preparing an electrode of an alkali metal ion battery.

[0117] According to a seventh aspect of the present invention there is provided an electrode for an alkali metal ion battery, namely an electrode comprising an electrode material according to the fifth aspect of the present invention.

[0118] According to an eighth aspect of the present invention there is provided the use of an electrode according to the seventh aspect of the present invention for preparing an alkali metal ion battery.

[0119] According to a ninth aspect of the present invention, there is provided an alkali metal ion battery comprising an electrode according to the seventh aspect of the present invention.

[0120] According to a tenth aspect of the present invention, there is provided a use according to the sixth or eighth aspect of the present invention, an electrode according to the seventh aspect of the present invention, or a battery according to the ninth aspect of the present invention, wherein the alkali metal ion battery is a lithium ion battery, a sodium ion battery, or a potassium ion battery.

[0121] In one embodiment of the present invention, the particulate material is a surface-modified particulate material.

[0122] Process Control Systems In a preferred embodiment of the present invention, the reactor is equipped with at least one process control system. Examples of such systems include, but are not limited to, a process control system that controls the flow rate of a mixture of liquefied petroleum gas and air in the burner based on a predetermined reaction temperature and measurements from at least one temperature transducer located along the inlet and / or outlet conduits. Preferably, the process control system employs a feedback control algorithm. For example, the algorithm can be a proportional-integral-derivative control or a model predictive control.

[0123] Other aspects of the present invention will become apparent to those skilled in the art upon review of the following description of specific embodiments of the invention.

[0124] definition In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only, and is not intended to be limiting. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0125] Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprise", "comprising", and the like are to be construed in their inclusive sense, i.e., "including but not limited to," rather than in their exclusive or exhaustive sense.

[0126] As used herein, the phrase "consisting of" excludes any element, step, or ingredient not specified in the claim. When the phrase "consists of" (or variations thereof) appears in a section of the body of a claim rather than immediately following the preamble, it limits only the elements recited in that section; other elements are not excluded from the claim as a whole. As used herein, the phrase "consisting essentially of" limits a claim to the elements or methods specified, and to those that do not materially affect the basic and novel characteristics of the claimed subject matter.

[0127] With respect to the terms "comprising," "consisting of," and "consisting essentially of," when one of these three terms is used herein, the presently disclosed and claimed subject matter may also include the use of either of the other two terms. Thus, in some embodiments not otherwise expressly stated, any instance of "comprising" may be replaced with "consisting of" or alternatively, "consisting essentially of."

[0128] Except in the working examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein should be understood as being modified in all instances by the term "about." The examples are not intended to limit the scope of the invention. Hereinafter, or where otherwise stated, "%" means "% by weight," "ratio" means "ratio by weight," and "parts" means "parts by weight."

[0129] As used herein, the term "substantially" shall mean, where relevant, including more than 50% by weight, unless otherwise indicated.

[0130] The recitation of numerical ranges using endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0131] Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive or, not an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0132] The terms "preferred" and "preferably" refer to embodiments of the invention that may offer certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention.

[0133] It should also be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0134] As used herein, when referring to numbers within a numerical range, the terms "about," "approximately," and "substantially" are understood to refer to a range of -10% to +10% of the referenced number, preferably -5% to +5% of the referenced number, more preferably -1% to +1% of the referenced number, and most preferably -0.1% to +0.1% of the referenced number. Furthermore, when referring to a numerical range, these terms should be interpreted as providing support for a claim directed to any number or subset of numbers within that range. For example, a disclosure of 1 to 10 should be interpreted as supporting ranges of 1 to 8, 3 to 7, 1 to 9, 3.6 to 4.6, 3.5 to 9.9, 8 to 10, etc.

[0135] The term "short chain hydrocarbon" refers to hydrocarbons having four or fewer carbon atoms.

[0136] The term "turbulent flow" refers to a flow characterized by irregular motion of particles in the fluid and / or by chaotic changes in pressure and flow velocity. Turbulent flow typically has a Reynolds number of 2000 or greater.

[0137] The term "laminar flow" refers to a fluid flowing in parallel layers without breaks between those layers, as opposed to turbulent flow. The Reynolds number for turbulent flow is typically less than 2000.

[0138] The term "Geldart Classification" refers to a classification of materials into four groups based on their behavior when fluidized: A - Breathable, B - Foamable, C - Cohesive, D - Spoutable.

[0139] In some embodiments, the terms "carrier gas" and "inert gas" are used interchangeably.

[0140] Although exemplary embodiments of the disclosed technology are described in detail herein, it should be understood that other embodiments are contemplated. Accordingly, the disclosed technology is not intended to be limited in scope to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The disclosed technology is capable of other embodiments and of being practiced or carried out in various ways. [Brief explanation of the drawings]

[0141] Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0142] [Figure 1] 1 shows the inlet and outlet conduits of an embodiment of a reactor that includes three bends. [Figure 2] 1 shows the inlet and outlet conduits of another embodiment of the reactor, including six semicircular bends and multiple introduction points for carrier gas, inert gas, and / or hydrocarbon gas. [Figure 3] 1 illustrates a particular embodiment of a reactor for use in the surface modification of particulate materials. DETAILED DESCRIPTION OF THE INVENTION

[0143] Cathode Material Without wishing to be bound by theory, it is understood by those skilled in the art that the carbon coating of the cathode material not only increases Li ion and electron transfer, but also protects the cathode material from side reactions at the electrolyte interface. Furthermore, it is understood by those skilled in the art that carbon-coated cathode materials such as LFP increase electrical conductivity, reduce the internal resistance of the battery, and generally improve the electrochemical performance of the battery.

[0144] Without wishing to be bound by theory, surface coating has been reported to be an effective and economical way to overcome the problems of low specific capacity and poor cycling stability in cathode materials. Carbon-based materials are a good choice for coating due to their excellent chemical stability and physical properties. The carbon coating aims to provide additional ion diffusion paths and promote electron transport through the cathode surface interface. Meanwhile, the carbon coating can not only control the surface chemical stability and structural changes of the cathode material during the lithiation / delithiation reaction, but also suppress the adverse reaction between the cathode and the electrolyte that causes cycling instability. Additionally, the carbon coating forms a physical covering layer to reduce electrolyte corrosion, which increases the specific capacity, enhances thermal stability, and extends the cycling life of LIBs.

[0145] A current limitation of carbon coating of cathode materials is the uniformity of the coating and fine control over the thickness (and therefore weight %) of the carbon coating on the material. The present invention, in its preferred embodiments, addresses these limitations.

[0146] In one embodiment of the present invention, the feed material comprises a cathode material. In one embodiment, the cathode material is selected from one or more of the group including LFP (lithium iron phosphate), LFPM (lithium iron manganese phosphate), LNMO (lithium nickel manganese oxide), LMO (lithium manganese oxide), LiNiCoMn (NCM), LiCoO (LCO), NCA (nickel cobalt aluminum oxide), LiTiOMn, NMA (LiNiMnAlO), and LiNbMn. As will be appreciated by those skilled in the art, other cathode materials may be used as the feed material of the present invention, and such materials are within the scope of the present invention.

[0147] In some embodiments, the cathode material comprises a single crystal nickel-based cathode material, preferably NCM or NCA.

[0148] In some embodiments, the cathode material comprises a lithium-excess disordered rock salt cathode (DRX).

[0149] In some embodiments, the cathode material comprises a quaternary transition metal oxide layered framework, preferably NCMA (LiNiCoMnAlO 2 ).

[0150] In some embodiments, the cathode material comprises a sulfur-based cathode material, for example, one suitable for use in a Li-S battery.

[0151] In some embodiments, the cathode material is a doped cathode material.

[0152] In some embodiments, the doped cathode material comprises any one element or combination of two or more elements from the list including: Mg, Co, Al, Ni, Nb, Fe, Mn, Mo, V, Ti, Cr, Al, P, B, Zr, Ru, F, S, Na, Nd, Cu, Bi, Y, Pd, Pt, Ta, Ga, or Si.

[0153] Example 1 Referring to the embodiment depicted in Figure 1, the reactor includes three bends 102, 104, and 106. Feed material 100 enters the reactor and passes through a first inlet conduit 101, a first bend 102, a first outlet / second inlet conduit 103, a second bend 104, a second outlet / third inlet conduit 105, a third bend 106, and a third outlet conduit 107. The feed material is surface-modified by contacting it with a hydrocarbon gas at a temperature of about 500°C to about 1500°C under flowing inert gas (not shown). Surface-modified particulate material 108 exits the reactor at the end of the third outlet conduit 107.

[0154] Example 2 2, the reactor includes six bends 202, 204, 206, 208, 210, and 212. Feed material 200, fluidized by a carrier gas (not shown), enters the reactor and passes through a first inlet conduit 201, a first bend 202, a first outlet / second inlet conduit 203, a second bend 204, a second outlet / third inlet conduit 205, a third bend 206, a third outlet / fourth inlet conduit 207, a fourth bend 208, a fourth outlet / fifth inlet conduit 209, a fifth bend 210, a fifth outlet / sixth inlet conduit 211, a sixth bend 212, and a sixth outlet conduit 213. The fluidized feedstock is surface-modified by contacting it with a hydrocarbon gas at a temperature of about 500°C to about 1500°C under flowing inert gas. The hydrocarbon gas and / or inert gas can be mixed with the feedstock 200 in the form of a carrier gas. Alternatively, the hydrocarbon gas and / or inert gas can be mixed with the carrier gas. Furthermore, the hydrocarbon gas and / or inert gas and / or carrier gas can also be introduced into the reactor at multiple points along the inlet / outlet conduits. As a non-limiting example, FIG. 2 shows hydrocarbon gas 215, inert gas 216, and carrier gas 217 being introduced into the reactor.

[0155] Note that the feedstock 200 may also be fed into the reactor from the top of the reactor (not shown) instead of the bottom, as shown in FIG.

[0156] Example 3 3 illustrates a reactor and a method for using the reactor to prepare carbon-coated graphite particles. Uncoated graphite particles 300 are introduced into a feed control system where they are fluidized by a carrier gas 303 containing argon and 5% hydrogen. The carrier gas is at a flow rate of approximately 0.05 sm 3 / h. The carrier gas is preheated in a heat exchanger where it receives heat from the flow of carbon-coated graphite particles mixed with the carrier gas and / or inert gas and / or unreacted hydrocarbon gas 308. The preheated carrier gas 303 is directed to a feed control system to facilitate fluidization of the graphite particles. The graphite particles are fed at a feed rate of about 5 kg / h and a mass of about 2090 kg / m 3 has a particle density of

[0157] Approximately 1.7% volume fraction and approximately 7 kg / m 2 Fluidized uncoated graphite particles 301 having a solids flux of s enter reactor 307, which contains inlet / outlet conduits as described in Example 2. Each inlet / outlet conduit has the dimensions outlined in Table 1. [Table 1]

[0158] The fluidized graphite particles have a flow rate of about 0.2 m / s within reactor 307 and a residence time of about 15 minutes. The uncoated particles are contacted with a hydrocarbon gas, propane. The propane may be introduced in a feed control system and mixed with a carrier gas. Additionally, the propane may be introduced at various points along the inlet / outlet conduits, for example, at one or more of introduction points 304, 305, and 306. Those skilled in the art will appreciate that an inert gas and / or a carrier gas may also be introduced at various locations along the inlet / outlet conduits.

[0159] The reactor is placed in a split-type electrically heated muffle furnace (not shown) and maintained at an operating temperature of about 1000° C. and an operating pressure of about 50 kPa.

[0160] The carbon-coated graphite particles mixed with the carrier gas and / or inert gas, and / or unreacted hydrocarbon gas 309 are directed to a sintered metal filter. Argon 311 is introduced into the filter to facilitate gas-solid separation. The carbon-coated graphite particles 312 are collected and stored in a metal drum, while the separated gas 310 is recycled back to the heat exchanger after being compressed by compressor 302. In some embodiments, the spent carrier gas and / or inert gas 313 is removed, and preferably the removed gas is completely combusted within the reactor muffle or in a separate vessel.

[0161] Although the present invention will be described with reference to specific examples, those skilled in the art will appreciate that the present invention can be embodied in many other forms.

[0162] Other embodiments of the invention described herein are defined in the following paragraphs. 1. A CVD reactor, in particular a spout flow reactor, for preparing particulate materials, comprising: a first inlet conduit; a first bend having one end located at the end of the first inlet conduit and another end located at the beginning of the first outlet conduit; A reactor in which a particulate material is prepared by flowing a feedstock through an inlet conduit and an outlet conduit while contacting it with a hydrocarbon gas at a temperature of about 500°C to about 1500°C under a flowing inert gas. 2. The reactor described in paragraph 1, wherein the feedstock has a residence time in the reactor of from about 4 minutes to about 100 minutes. 3. The reactor of any one or more of the preceding paragraphs, wherein the feed has a residence time of about 15 minutes to 45 minutes. 4. The reactor of any one or more of the preceding paragraphs, wherein the feed material is selected from the group consisting of carbonaceous particulate materials, metallic lithium, lithium titanate, tin-based alloys, cathode materials, and silicon-based materials. 5. The reactor of any one or more of the preceding paragraphs, wherein the silicon-based material preferably comprises silicon particles having a size of from about 10 nm to about 400 nm. 6. The reactor of any one or more of the preceding paragraphs, wherein the silicon-based material comprises silicon particles coated with a carbonaceous material or silicon carbide. 7. The reactor of any one or more of the preceding paragraphs, wherein the coated silicon particles comprise graphite-coated silicon nanoparticles and / or carbon-coated silicon nanoparticles, preferably in the form of clusters and agglomerates. 8. The reactor of any one or more of the preceding paragraphs, wherein the carbonaceous particulate material is selected from the group consisting of natural graphite, synthetic graphite, exfoliated graphite, amorphous graphite, amorphous carbon, carbon black, coke, graphene, graphene fibers, and graphene nanotubes. 9. The reactor of any one or more of the preceding paragraphs, wherein the carbonaceous particulate material at least substantially encapsulates or surrounds the secondary material. 10. The reactor of any one or more of the preceding paragraphs, wherein the secondary material is selected from the group comprising metallic lithium, lithium titanate, tin-based alloys, and silicon-based materials. 11. The reactor of any one or more of the preceding paragraphs, wherein the secondary material comprises silicon particles or silicon nanoparticles. 12. A reactor according to any one or more of the preceding paragraphs, further comprising n bends, each bend having an n+1th inlet conduit and an n+1th outlet conduit, the nth outlet conduit being in fluid communication with the n+1th inlet conduit and defining the n+1th inlet conduit. 13. The reactor of any one or more of the preceding paragraphs, further comprising a second bend having a second inlet conduit and a second outlet conduit, the first outlet conduit being in fluid communication with the second inlet conduit and defining the second inlet conduit. 14. A reactor according to any one or more of the preceding paragraphs, comprising one or more inert gas inlets, preferably two or more inert gas inlets, along the inlet and / or outlet conduits for introducing an inert gas into the reactor. 15. The reactor of any one or more of the preceding paragraphs, wherein the bend is angled from about 0° to about 180°, or from about 30° to about 150°, or from about 60° to about 120°. 16. The reactor of any one or more of the preceding paragraphs, wherein the bend is angled at about 45°, about 90°, or about 135°. 17. The reactor of any one or more of the preceding paragraphs, wherein the bend is semicircular. 18. A reactor according to any one or more of the preceding paragraphs, wherein the cross section of each respective conduit is circular. 19. A reactor according to any one or more of the preceding paragraphs, wherein each respective conduit is of the same cross-sectional area. 20. The reactor of any one or more of the preceding paragraphs, wherein the inert gas is helium, nitrogen, argon, or neon, or a combination thereof. 21. The reactor of any one or more of the preceding paragraphs, wherein the feedstock is contacted with the hydrocarbon gas at a temperature of from about 600°C to about 1200°C. 22. A reactor according to any one or more of the preceding paragraphs, wherein the feedstock is contacted with the hydrocarbon gas at a temperature of about 1000°C. 23. The reactor of any one or more of the preceding paragraphs, wherein the feedstock is contacted with the hydrocarbon gas at a pressure of from about 25 kPag to about 75 kPag. 24. The reactor of any one or more of the preceding paragraphs, wherein the feedstock is contacted with the hydrocarbon gas at a pressure of 50 kPag. 25. The reactor of any one or more of the preceding paragraphs, wherein the hydrocarbon gas is an aliphatic or aromatic hydrocarbon, which may optionally contain one or more nitrogen atoms, and is selected from the group consisting of methane, ethane, ethylene, propane, propene, acetylene, butane, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, acetonitrile, pyrrole, quinoline, isoquinoline, acridine, pyrazine, quinoxaline, imidazole, benzimidazole, purine, pyrazole, indazole, pyrimidine quinazoline, pyrimidine, quinazoline, pyridazine, cinnoline, pyridine, dimethylformamide (DMF), nitromethane, benzene, toluene, xylene, and combinations thereof, preferably methane or a short chain hydrocarbon. 26. The reactor according to any one of claims 1 to 24, wherein the hydrocarbon gas is propane. 27. The reactor of any one or more of the preceding paragraphs, further comprising a feed control system for supplying feed materials to the reactor. 28. A reactor according to any one or more of the preceding paragraphs, wherein the feed control system comprises a compartment through which the feed material is fluidized by a supply of carrier gas and introduced into the reactor. 29. The reactor of any one or more of the preceding paragraphs, wherein the carrier gas comprises helium, nitrogen, argon, or neon, or a combination thereof. 30. The reactor of any one or more of the preceding paragraphs, wherein the carrier gas further comprises about 5% v / v hydrogen. 31. A reactor according to any one or more of the preceding paragraphs, wherein the carrier gas is preheated. 32. A reactor according to any one or more of the preceding paragraphs, wherein the carrier gas is preheated by receiving heat from the particulate material and spent carrier gas in a heat exchanger. 33. The reactor of any one or more of the preceding paragraphs, wherein the heat exchanger is a pipe-in-pipe heat exchanger. 34. A reactor according to any one or more of the preceding paragraphs, wherein the feed material is fed in batches. 35. A reactor according to any one or more of the preceding paragraphs, wherein the feed material is fed in batches using a lock hopper. 36. A reactor according to any one or more of the preceding paragraphs, wherein the feedstock is fed continuously. 37. The reactor of any one or more of the preceding paragraphs, wherein the feedstock is fed at a rate of from about 0.1 kg / h to about 10 kg / h. 38. The reactor of any one or more of the preceding paragraphs, wherein the feedstock is fed at about 5 kg / h. 39. A reactor according to any one or more of the preceding paragraphs, further comprising heating means for heating the reactor. 40. A reactor according to any one or more of the preceding paragraphs, wherein the heating means comprises a burner for combusting a mixture of gaseous fuel and air. 41. A reactor according to any one or more of the preceding paragraphs, wherein the heating means comprises an electrically heated furnace. 42. The reactor of any one or more of the preceding paragraphs, further comprising separation means in fluid communication with the outlet conduit for separating the particulate material from the gas. 43. The reactor of any one or more of the preceding paragraphs, wherein the separating means comprises a sintered metal filter. 44. A reactor according to any one or more of the preceding paragraphs, wherein the separated gas is recycled back into the reactor. 45. A reactor according to any one or more of the preceding paragraphs, wherein the separated gas is compressed before recycling. 46. ​​A method for preparing a particulate material, comprising flowing a feed material through a CVD reactor, particularly a jet flow reactor, the CVD reactor comprising: a first inlet conduit; a first bend having one end located at the end of the first inlet conduit and another end located at the beginning of the first outlet conduit; The process wherein the feedstock flows through an inlet conduit and an outlet conduit while contacting a hydrocarbon gas at a temperature of about 500°C to about 1500°C under a flowing inert gas. 47. The method of any one or more of the preceding paragraphs, wherein the feedstock has a residence time in the reactor of from about 4 minutes to about 100 minutes. 48. The method of any one or more of the preceding paragraphs, wherein the feedstock has a residence time of about 15 minutes to 45 minutes. 49. The method of any one or more of the preceding paragraphs, wherein the feed material is selected from the group consisting of carbonaceous particulate materials, metallic lithium, lithium titanate, tin-based alloys, and silicon-based materials. 50. The method of any one or more of the preceding paragraphs, wherein the silicon-based material preferably comprises silicon particles having a size of from about 10 nm to about 400 nm. 51. The method of any one or more of the preceding paragraphs, wherein the silicon-based material comprises silicon particles coated with a carbonaceous material or silicon carbide. 52. The method of any one or more of the preceding paragraphs, wherein the coated silicon particles comprise graphite-coated silicon nanoparticles and / or carbon-coated silicon nanoparticles, preferably in the form of clusters and agglomerates. 53. The method of any one or more of the preceding paragraphs, wherein the carbonaceous particulate material is selected from the group consisting of natural graphite, synthetic graphite, exfoliated graphite, amorphous carbon, carbon black, coke, graphene, graphene fibers, and graphene nanotubes. 54. The method of any one or more of the preceding paragraphs, wherein the carbonaceous particulate material at least substantially encapsulates or surrounds the secondary material. 55. The method of any one or more of the preceding paragraphs, wherein the secondary material is selected from the group comprising metallic lithium, lithium titanate, tin-based alloys, and silicon-based materials. 56. The method of any one or more of the preceding paragraphs, wherein the secondary material comprises silicon particles or silicon nanoparticles. 57. The method of any one or more of the preceding paragraphs, wherein the reactor further comprises n bends, each bend having an n+1th inlet conduit and an n+1th outlet conduit, the nth outlet conduit being in fluid communication with the n+1th inlet conduit and defining the n+1th inlet conduit. 58. The method of any one or more of the preceding paragraphs, wherein the reactor further comprises a second bend having a second inlet conduit and a second outlet conduit, the first outlet conduit being in fluid communication with the second inlet conduit and defining the second inlet conduit. 59. The method of any one or more of the preceding paragraphs, comprising introducing an inert gas into the reactor via one or more inert gas inlets, preferably via two or more inert gas inlets, along the inlet conduit and / or the outlet conduit. 60. The method of any one or more of the preceding paragraphs, wherein the bend is angled between about 0° and about 180°, or between about 30° and about 150°, or between about 60° and about 120°. 61. The method of any one or more of the preceding paragraphs, wherein the bend is angled at about 45°, about 90°, or about 135°. 62. The method of any one or more of the preceding paragraphs, wherein the bend is semicircular. 63. The method of any one or more of the preceding paragraphs, wherein the cross section of each respective conduit is circular. 64. The method of any one or more of the preceding paragraphs, wherein each respective conduit is of the same cross-sectional area. 65. The method of any one or more of the preceding paragraphs, wherein the inert gas is helium, nitrogen, argon, or neon, or a combination thereof. 66. The method of any one or more of the preceding paragraphs, wherein the feedstock is contacted with the hydrocarbon gas at a temperature of from about 600°C to about 1200°C. 67. The method of any one or more of the preceding paragraphs, wherein the feed material is contacted with the hydrocarbon gas at a temperature of about 1000°C. 68. The method of any one or more of the preceding paragraphs, wherein the feedstock is contacted with the hydrocarbon gas at a pressure of from about 25 kPag to about 75 kPag. 69. The method of any one or more of the preceding paragraphs, wherein the feedstock is contacted with the hydrocarbon gas at a pressure of 50 kPag. 70. The method of any one or more of the preceding paragraphs, wherein the hydrocarbon gas is an aliphatic or aromatic hydrocarbon, which may optionally contain one or more nitrogen atoms, and is selected from the group consisting of methane, ethane, ethylene, propane, propene, acetylene, butane, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, acetonitrile, pyrrole, quinoline, isoquinoline, acridine, pyrazine, quinoxaline, imidazole, benzimidazole, purine, pyrazole, indazole, pyrimidine quinazoline, pyrimidine, quinazoline, pyridazine, cinnoline, pyridine, dimethylformamide (DMF), nitromethane, benzene, toluene, xylene, and combinations thereof, preferably methane or a short chain hydrocarbon. 71. The method of any one or more of the preceding paragraphs, wherein the hydrocarbon gas is propane. 72. The method of any one or more of the preceding paragraphs, further comprising the step of feeding the feed material to the reactor using a feed control system. 73. The method of any one or more of the preceding paragraphs, wherein the feed control system comprises a compartment in which the feed material is fluidized by a supply of carrier gas and introduced into the reactor. 74. The method of any one or more of the preceding paragraphs, wherein the carrier gas comprises helium, nitrogen, argon, or neon, or a combination thereof. 75. The method of any one or more of the preceding paragraphs, wherein the carrier gas further comprises about 5% v / v hydrogen. 76. The method of any one or more of the preceding paragraphs, wherein the carrier gas is preheated. 77. The method of any one or more of the preceding paragraphs, wherein the carrier gas is preheated by receiving heat from the particulate material and spent carrier gas in a heat exchanger. 78. The method of any one or more of the preceding paragraphs, wherein the heat exchanger is a pipe-in-pipe heat exchanger. 79. The method of any one or more of the preceding paragraphs, wherein the feed material is fed in batches. 80. The method of any one or more of the preceding paragraphs, wherein the feed material is fed in batches using a lock hopper. 81. The method of any one or more of the preceding paragraphs, wherein the feed material is fed continuously. 82. The method of any one or more of the preceding paragraphs, wherein the feed material is fed at a rate of from about 0.1 kg / h to about 10 kg / h. 83. The method of any one or more of the preceding paragraphs, wherein the feed material is fed at about 5 kg / h. 84. The method of any one or more of the preceding paragraphs, wherein the reactor further comprises a heating means for heating the reactor. 85. The method of any one or more of the preceding paragraphs, wherein the heating means comprises a burner for combusting a mixture of gaseous fuel and air. 86. The method of any one or more of the preceding paragraphs, wherein the heating means includes an electrically heated furnace. 87. The method of any one or more of the preceding paragraphs, further comprising separating the particulate material from the gas using a separation means in fluid communication with the outlet conduit. 88. The method of any one or more of the preceding paragraphs, wherein the separating means comprises a sintered metal filter. 89. The method of any one or more of the preceding paragraphs, wherein the separated gas is recycled back to the reactor. 90. The method of any one or more of the preceding paragraphs, wherein the separated gas is compressed before recycling. 91. A particulate material obtained or obtainable from a method according to any one or more of the preceding paragraphs. 92. A particulate material according to any one or more of the preceding paragraphs, wherein the material is silicon particles or silicon carbide particles coated with at least one layer of a carbonaceous material. 93. A particulate material according to any one or more of the preceding paragraphs, wherein the silicon particles or silicon carbide particles are coated with one layer of carbonaceous material, the layer having a thickness of from about 0.1 nm to about 100 nm, or from about 0.025% to about 1000% of the particle size, preferably from about 5 nm to about 30 nm, or from about 1.25% to about 300% of the particle size, more preferably from about 5 nm to about 20 nm, or from about 1.25% to about 200% of the particle size. 94. A particulate material according to any one or more of the preceding paragraphs, wherein the silicon particles or silicon carbide particles are coated with two layers of carbonaceous material, the layers having a thickness of from about 0.1 nm to about 400 nm, or from about 0.025% to about 4000% of the particle size, preferably from about 100 nm to about 300 nm, or from about 25% to about 3000% of the particle size, more preferably from about 100 nm to about 250 nm, or from about 25% to about 2500% of the particle size, and especially preferably from about 100 nm to about 200 nm, or from about 25% to about 2000% of the particle size. 95. A particulate material according to any one or more of the preceding paragraphs, wherein the coated silicon particles comprise graphite-coated silicon nanoparticles and / or carbon-coated silicon nanoparticles. 96. The particulate material of any one or more of the preceding paragraphs, wherein the coated silicon particles comprise about 3% to about 20% of a carbonaceous material, preferably graphite, amorphous carbon, and / or mixtures thereof. 97. A particulate material according to any one or more of the preceding paragraphs, wherein the coated silicon particles are in the form of clusters and / or agglomerates. 98. Use of a particulate material according to any one or more of the preceding paragraphs for preparing an electrode material. 99. An electrode material comprising a particulate material according to any one or more of the preceding paragraphs. 100. Use of an electrode material according to any one or more of the preceding paragraphs for preparing an electrode of an alkali metal ion battery. 101. An electrode for an alkali metal ion battery, wherein the electrode comprises an electrode material according to any one or more of the preceding paragraphs. 102. Use of an electrode according to any one or more of the preceding paragraphs for preparing an alkali metal ion battery. 103. An alkali metal ion battery comprising an electrode according to any one or more of the preceding paragraphs. 104. The use according to any one or more of the preceding paragraphs, the electrode according to any one or more of the preceding paragraphs, or the battery according to any one or more of the preceding paragraphs, wherein the alkali metal ion battery is a lithium ion battery, a sodium ion battery, or a potassium ion battery.

Claims

1. 1. A CVD reactor for preparing a particulate material, said reactor comprising: a first inlet conduit; a first bend having one end located at the end of the first inlet conduit and another end located at the beginning of the first outlet conduit; a reactor in which the particulate material is prepared by flowing a feedstock through the inlet conduit and the outlet conduit while contacting it with a hydrocarbon gas at a temperature of about 500°C to about 1500°C under a flowing inert gas.

2. 10. The reactor of claim 1, wherein the feedstock has a residence time in the reactor of from about 4 minutes to about 100 minutes, preferably, the residence time is from about 15 minutes to 45 minutes.

3. 3. The reactor of claim 1 or 2, wherein the feed material is selected from the group consisting of carbonaceous particulate materials, metallic lithium, lithium titanate, tin-based alloys, cathode materials, silicon carbon-based materials, and silicon-based materials.

4. The reactor of claim 3, wherein the silicon-based material preferably comprises silicon particles having a size of about 10 nm to about 400 nm.

5. 5. The reactor of claim 3 or 4, wherein the carbonaceous particulate material is selected from the group consisting of natural graphite, synthetic graphite, exfoliated graphite, amorphous graphite, amorphous carbon, carbon black, coke, graphene, graphene fibers, and graphene nanotubes.

6. The reactor of any one of claims 3 to 5, wherein the carbonaceous particulate material at least substantially encapsulates or surrounds the secondary material.

7. 7. The reactor of any one of claims 1 to 6, further comprising n bends, each bend having an n+1 inlet conduit and an n+1 outlet conduit, the n outlet conduit being in fluid communication with the n+1 inlet conduit and defining the n+1 inlet conduit.

8. 8. The reactor according to any one of claims 1 to 7, comprising one or more inert gas inlets, preferably two or more inert gas inlets, along the inlet conduit and / or the outlet conduit, for introducing the inert gas into the reactor.

9. 9. The reactor of any one of claims 1 to 8, wherein the bend is angled at about 0° to about 180°, or about 30° to about 150°, or about 60° to about 120°, preferably the bend is angled at about 45°, about 90°, or about 135°.

10. The reactor of any one of claims 1 to 9, wherein the feedstock is contacted with the hydrocarbon gas at a pressure of from about 25 kPag to about 75 kPag, preferably at a pressure of about 50 kPag.

11. 11. The reactor of any one of claims 1 to 10, wherein the hydrocarbon gas is an aliphatic or aromatic hydrocarbon, which may optionally contain one or more nitrogen atoms, and is selected from the group consisting of methane, ethane, ethylene, propane, propene, acetylene, butane, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, acetonitrile, pyrrole, quinoline, isoquinoline, acridine, pyrazine, quinoxaline, imidazole, benzimidazole, purine, pyrazole, indazole, pyrimidine quinazoline, pyrimidine, quinazoline, pyridazine, cinnoline, pyridine, dimethylformamide (DMF), nitromethane, benzene, toluene, xylene, and combinations thereof, preferably methane or short chain hydrocarbons, preferably the hydrocarbon gas is propane.

12. 12. The reactor of any one of claims 1 to 11, further comprising a feed control system for feeding the feed material to the reactor, the feed control system comprising a compartment through which the feed material is fluidized by a supply of a carrier gas and introduced into the reactor, preferably the carrier gas further comprising about 1% to about 10% v / v of hydrogen.

13. The reactor of any one of claims 1 to 12, further comprising a heating means for heating the reactor.

14. 14. A reactor according to any preceding claim, further comprising separation means in fluid communication with said outlet conduit for separating said particulate material from gas, preferably said separation means comprising a sintered metal filter.

15. 1. A method of preparing a particulate material, the method comprising flowing a feed material through a CVD reactor, the CVD reactor comprising: a first inlet conduit; a first bend having one end located at the end of the first inlet conduit and another end located at the beginning of the first outlet conduit; The process wherein the feedstock flows through the inlet conduit and the outlet conduit while contacting a hydrocarbon gas at a temperature of about 500°C to about 1500°C under a flowing inert gas.

16. 16. The method of claim 15, wherein the feedstock has a residence time in the reactor of from about 4 minutes to about 100 minutes, preferably, the residence time is from about 15 minutes to 45 minutes.

17. 17. The method of claim 15 or 16, wherein the feed material is selected from the group consisting of carbonaceous particulate materials, metallic lithium, lithium titanate, tin-based alloys, and silicon-based materials.

18. The method of claim 17, wherein the silicon-based material comprises silicon particles preferably having a size of about 10 nm to about 400 nm.

19. 19. The method of claim 17 or 18, wherein the carbonaceous particulate material is selected from the group consisting of natural graphite, synthetic graphite, exfoliated graphite, amorphous carbon, carbon black, coke, graphene, graphene fibers, and graphene nanotubes.

20. 20. The method of claim 19, wherein the carbonaceous particulate material at least substantially encapsulates or surrounds the secondary material.

21. 21. The method of any one of claims 15 to 20, wherein the reactor further comprises n bends, each bend having an n+1 inlet conduit and an n+1 outlet conduit, the n outlet conduit being in fluid communication with the n+1 inlet conduit and defining the n+1 inlet conduit.

22. 22. The method of any one of claims 15 to 21, comprising introducing the inert gas into the reactor via one or more inert gas inlets, preferably via two or more inert gas inlets along the inlet conduit and / or the outlet conduit.

23. 23. The method of any one of claims 15 to 22, wherein the bend is angled at about 0° to about 180°, or about 30° to about 150°, or about 60° to about 120°, preferably the bend is angled at about 45°, about 90°, or about 135°.

24. A process according to any one of claims 15 to 23, wherein the feedstock is contacted with the hydrocarbon gas at a pressure of from about 25 kPag to about 75 kPag, preferably at a pressure of about 50 kPag.

25. 25. The method of any one of claims 15 to 24, wherein the hydrocarbon gas is an aliphatic or aromatic hydrocarbon, which may optionally contain one or more nitrogen atoms, and is selected from the group consisting of methane, ethane, ethylene, propane, propene, acetylene, butane, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, acetonitrile, pyrrole, quinoline, isoquinoline, acridine, pyrazine, quinoxaline, imidazole, benzimidazole, purine, pyrazole, indazole, pyrimidine quinazoline, pyrimidine, quinazoline, pyridazine, cinnoline, pyridine, dimethylformamide (DMF), nitromethane, benzene, toluene, xylene, and combinations thereof, preferably methane or short chain hydrocarbons, preferably the hydrocarbon gas is propane.

26. 26. The method of any one of claims 15 to 25, further comprising the step of feeding the feedstock to the reactor using a feed control system, the feed control system comprising a compartment through which the feedstock is fluidized by a supply of carrier gas and introduced into the reactor, preferably the carrier gas further comprising about 5% v / v hydrogen.

27. 27. The method of any one of claims 15 to 26, wherein the reactor further comprises a heating means for heating the reactor.

28. 28. A method according to any one of claims 15 to 27, further comprising separating the particulate material from the gas using separation means in fluid communication with the outlet conduit, preferably wherein the separation means comprises a sintered metal filter.

29. A particulate material obtained or obtainable from the method according to any one of claims 15 to 28.

30. 30. An alkali metal ion battery comprising an electrode, the electrode comprising an electrode material comprising the particulate material of claim 29, wherein the alkali metal ion battery is a lithium ion battery, a sodium ion battery, or a potassium ion battery.

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