Silicon-carbon powder and manufacturing equipment thereof, and dispersion and adsorption process based on silicon-carbon powder

Abstract

The invention provides silicon-carbon powder and manufacturing equipment thereof, and a dispersion and adsorption process based on the silicon-carbon powder. The dispersion and adsorption process based on the silicon carbon powder comprises the following steps: obtaining porous carbon powder; modifying gas is introduced into the porous carbon powder for fluidization treatment, the modifying gas at least comprises a silane compound and a hydrocarbon compound, and the flow velocity of the modifying gas is 10 sccm to 200 sccm; the gas for modification is subjected to plasma treatment, plasma gas is introduced into the porous carbon powder, the porous carbon powder and the plasma gas can be uniformly dispersed and mixed, the plasma power supply power is 100-4000 W, the discharge voltage is 500-5000 V, the discharge current is 0.2-3 A, and the temperature is 50-400 DEG C. According to the dispersion and adsorption process based on the silicon carbon powder, the dispersion uniformity of the porous carbon and the plasma gas can be better optimized, so that the doping and coating uniformity is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas and solid mixing, and in particular to a silicon-carbon powder and a manufacturing device thereof, and a dispersion adsorption process based on the silicon-carbon powder. Background Art

[0002] Lithium-based active materials, in which there are many substances doped and coated, such as the invention patent application with application number CN202210619600.0, which is the preparation of lithium iron manganese phosphate, a positive electrode material, specifically, the surface of the lithium iron manganese phosphate material is treated with plasma for non-metallic doping and coating. The doping and coating treatment efficiency is high and has no effect on the performance of the lithium iron manganese phosphate. However, since the lithium iron manganese phosphate is a powder, there is agglomeration between the lithium iron manganese phosphate particles and accumulation between the particles, which leads to insufficient mixing of the lithium iron manganese phosphate and the plasma gas, and thus the surface of the lithium iron manganese phosphate is not locally plasma treated, resulting in poor uniformity of non-metallic doping and coating of the lithium iron manganese phosphate. In particular, for the preparation of silicon-carbon powder, a negative electrode material for lithium batteries, the smaller the particle size of the porous carbon, the more difficult it is to disperse, resulting in poor dispersion uniformity of the porous carbon and the plasma gas, thereby affecting the uniform doping and coating of silicon in the porous carbon, which has a great influence on the electrochemical properties of the silicon-carbon powder, a negative electrode material for lithium batteries. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a silicon-carbon powder and its production equipment, and a dispersion adsorption process based on silicon-carbon powder, which can better optimize the dispersion uniformity of porous carbon and plasma gas, thereby improving the uniformity of doping and coating.

[0004] The objective of the present invention is achieved through the following technical solutions: A dispersion adsorption process based on silicon-carbon powder comprises the following steps: obtaining porous carbon powder; A modifying gas is introduced into the porous carbon powder for fluidization treatment, wherein the modifying gas comprises at least a silane compound and a hydrocarbon compound, and the flow rate of the modifying gas is 10 sccm to 200 sccm; The modifying gas is subjected to plasma treatment, and plasma gas is introduced into the porous carbon powder, so that the porous carbon powder and the plasma gas can be evenly dispersed and mixed. The plasma power supply power is 100W~4000W, the discharge voltage is 500V~5000V, the discharge current is 0.2A~3A, and the temperature is 50℃~400℃.

[0005] In one embodiment, the hydrocarbon compound is at least one of methane, ethane and acetylene.

[0006] In one embodiment, the silane compound is monosilane and / or disilane.

[0007] In one embodiment, the particle size distribution of the porous carbon powder is 0.2 μm to 12 μm, and D50 is 1 μm to 4 μm.

[0008] In one embodiment, the pore size distribution of the porous carbon powder is 0.2 nm~3.5 nm, and the pore volume is 0.25 cm 3 / g~1cm 3 / g, and the porosity is 60%~95%.

[0009] In one embodiment, the specific surface area of ​​the porous carbon powder is 1000 m 2 / g~2500m 2 / g.

[0010] In one embodiment, the bulk density of the porous carbon powder is 0.01 cm 3 / g~0.2cm 3 / g.

[0011] In one embodiment, before the step of introducing a modifying gas into the porous carbon powder for fluidization treatment and after the step of obtaining the porous carbon powder, the silicon-carbon powder-based dispersion adsorption process further includes the following steps: Inputting an inert gas into the porous carbon powder for fluidization treatment; The inert gas is subjected to plasma treatment.

[0012] In one embodiment, an inert gas is introduced into the porous carbon powder for fluidization treatment, and the flow rate of the inert gas is 5 sccm-200 sccm.

[0013] In one embodiment, the inert gas is subjected to plasma treatment, the plasma power supply power is 100W~1500W, the discharge voltage is 500V~5000V, the discharge current is 0.2A~3A, and the temperature is 50℃~400℃.

[0014] In one embodiment, the modifying gas also includes an inert gas.

[0015] In one embodiment, the inert gas is nitrogen and / or argon.

[0016] In one embodiment, the plasma treatment of the modifying gas specifically comprises the following steps: The modifying gas is subjected to a primary plasma treatment, wherein the flow rate of the modifying gas is 10 sccm to 50 sccm; the plasma power supply power is 100 W to 500 W, the discharge voltage is 500 V to 1500 V, the discharge current is 0.2 A to 0.8 A, and the temperature is 50° C. to 200° C.; The modifying gas is subjected to a secondary plasma treatment, wherein the flow rate of the modifying gas is 100 sccm to 200 sccm; the plasma power supply power is 2000 W to 4000 W, the discharge voltage is 2500 V to 5000 V, the discharge current is 1 A to 3 A, and the temperature is 300° C. to 400° C.; The modifying gas is subjected to three-stage plasma treatment, wherein the flow rate of the modifying gas is 50 sccm~100 sccm; the power of the plasma power supply is 500W~2000W, the discharge voltage is 1500 V~2500V, the discharge current is 0.5A~1.5A, and the temperature is 100°C~300°C.

[0017] A silicon-carbon powder manufacturing device, used for implementing the silicon-carbon powder-based dispersion adsorption process described in any of the above embodiments, the silicon-carbon powder manufacturing device comprising: Powder fluidization system; A feeding system, the feeding system is connected to the powder fluidization system, and the feeding system is used to add porous carbon powder to obtain the porous carbon powder and feed it into the powder fluidization system; A gas source system, the gas source system being connected to the powder fluidization system so as to introduce a modifying gas into the porous carbon powder for fluidization treatment; A plasma discharge system, the plasma discharge system being connected to the powder fluidization system to perform plasma treatment on the modifying gas; A control system, the control system being electrically connected to the gas source system and the plasma discharge system, respectively, to control the flow rate of the plasma gas, as well as the plasma power supply power, discharge voltage, discharge current and temperature; A discharging system is communicated with the powder fluidizing system to receive the porous carbon powder outputted from the powder fluidizing system.

[0018] A silicon-carbon powder is prepared by the silicon-carbon powder production equipment described in any of the above embodiments.

[0019] Compared with the prior art, the present invention has at least the following advantages: the dispersion and adsorption process based on silicon-carbon powder of the present invention introduces a modification gas into the porous carbon powder for fluidization treatment, adopts silane compounds and hydrocarbon compounds to perform plasma surface doping and coating on the surface of the porous carbon powder, promotes the flow rate of the modification gas to be 10sccm~200sccm, reduces the agglomeration between the porous carbon powder particles, better ensures the uniform dispersion of the porous carbon powder, and facilitates the plasma gas to be uniformly dispersed on the entire surface of the porous carbon powder particles and fully act, then, the modification gas is subjected to plasma treatment, and the plasma power supply power is 100W~ 4000W, discharge voltage is 500V~5000V, discharge current is 0.2A~3A, temperature is 50℃~400℃. On the basis of improving the uniformity of dispersion between porous carbon powder particles, plasma gas is introduced into the porous carbon powder, which effectively improves the uniform distribution of plasma gas on the surface of porous carbon powder particles, and then improves the uniform collision of plasma gas on the surface of porous carbon powder particles, so as to promote the complete doping and coating of silicon and carbon on the surface of porous carbon powder, that is, silicon and carbon are dispersed and spread on the surface of porous carbon powder, which effectively improves the doping and coating uniformity of the formed silicon-carbon powder, and improves the electrochemical properties of silicon-carbon powder, anode material of lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a flow chart of a dispersion adsorption process based on silicon-carbon powder according to one embodiment of the present invention; Figure 2 It is a structural schematic diagram of a silicon-carbon powder manufacturing device according to one embodiment of the present invention; Figure 3 This is a transmission electron microscope image of the silicon-carbon powder obtained in Example 2. DETAILED DESCRIPTION

[0022] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0023] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0025] The present application provides a dispersion adsorption process based on silicon-carbon powder. The above-mentioned dispersion adsorption process based on silicon-carbon powder includes the following steps: obtaining porous carbon powder; introducing a modification gas into the porous carbon powder for fluidization treatment, wherein the modification gas includes at least a silane compound and a hydrocarbon compound, and the flow rate of the modification gas is 10sccm~200sccm; performing plasma treatment on the modification gas, introducing plasma gas into the porous carbon powder, and the porous carbon powder and the plasma gas can be evenly dispersed and mixed, the plasma power supply power is 100W~4000W, the discharge voltage is 500V~5000V, the discharge current is 0.2A~3A, and the temperature is 50℃~400℃.

[0026] The above-mentioned dispersion and adsorption process based on silicon-carbon powder introduces a modifying gas into the porous carbon powder for fluidization treatment, and uses silane compounds and hydrocarbon compounds to perform plasma surface doping and coating on the surface of the porous carbon powder, so that the flow rate of the modifying gas is 10sccm~200sccm, which reduces the agglomeration between the porous carbon powder particles, better ensures the uniform dispersion of the porous carbon powder, and is conducive to the plasma gas being evenly dispersed on the entire surface of the porous carbon powder particles and fully acting. Then, the modifying gas is subjected to plasma treatment, the plasma power supply power is 100W~4000W, and the discharge voltage is 500V~5000V, discharge current 0.2A~3A, temperature 50℃~400℃. On the basis of improving the uniformity of dispersion between porous carbon powder particles, plasma gas is introduced into the porous carbon powder, which effectively improves the uniform distribution of plasma gas on the surface of porous carbon powder particles, and then improves the uniform collision of plasma gas on the surface of porous carbon powder particles, so as to promote the complete doping and coating of silicon and carbon on the surface of porous carbon powder, that is, silicon and carbon are dispersed and spread on the surface of porous carbon powder, which effectively improves the doping and coating uniformity of the formed silicon-carbon powder and improves the electrochemical performance of silicon-carbon powder, anode material of lithium battery.

[0027] In order to better understand the dispersion adsorption process based on silicon-carbon powder of the present application, the dispersion adsorption process based on silicon-carbon powder of the present application is further explained as follows: See also Figure 1 , a dispersion adsorption process based on silicon-carbon powder in one embodiment comprises the following steps: S100, obtaining porous carbon powder. It can be understood that the smaller the particle size of the porous carbon powder, the greater the agglomeration strength, which makes it difficult to evenly disperse the porous carbon powder, that is, there are more porous carbon powder particles aggregated together, even if the surface of the porous carbon powder particles is blocked, and then the formed plasma gas is difficult to evenly disperse on the surface of each porous carbon powder particle, and then the porous carbon powder particles and the plasma gas are not evenly dispersed, causing the plasma gas to collide only locally on the surface of the porous carbon powder particles, and the uniformity of the groups carried by the plasma gas dispersed and attached to the surface of the porous carbon powder is poor, that is, the doping and coating uniformity of the porous carbon powder is affected, and then the electrochemical performance of the silicon-carbon powder of the lithium battery negative electrode material is greatly affected. Therefore, the present application obtains porous carbon powder to improve the uniformity of the groups carried by the plasma gas dispersed and attached to the surface of the porous carbon powder, and then improve the electrochemical performance of the silicon-carbon powder of the lithium battery negative electrode material.

[0028] S200, introducing a modifying gas into the porous carbon powder for fluidization treatment, wherein the modifying gas includes at least a silane compound and a hydrocarbon compound, and the flow rate of the modifying gas is 10sccm~200sccm. It can be understood that the surface of the porous carbon powder is doped and coated with silane compounds and hydrocarbon compounds, so that the porous carbon surface is doped and coated with silicon and carbon, and when the flow rate of the modifying gas is 10sccm~200sccm, the uniform dispersion of the porous carbon powder can be better ensured, thereby reducing the agglomeration between the porous carbon powder particles, which is conducive to the plasma gas being evenly dispersed on the entire surface of the porous carbon powder particles and fully acting. Further, the modifying gas also includes an inert gas. Further, the inert gas is nitrogen and / or argon.

[0029] S300, plasma treatment is performed on the modified gas, and plasma gas is introduced into the porous carbon powder, so that the porous carbon powder and the plasma gas can be evenly dispersed and mixed, and the power of the plasma power supply is 100W~4000W, the discharge voltage is 500V~5000V, the discharge current is 0.2A~3A, and the temperature is 50℃~400℃. It can be understood that on the basis of fluidizing the porous carbon powder and reducing the agglomeration of the porous carbon powder particles, that is, on the basis of improving the uniformity of dispersion between the porous carbon powder particles, the plasma gas is introduced into the porous carbon powder, which effectively improves the uniform distribution of the plasma gas on the surface of the porous carbon powder particles, and further improves the uniform collision of the plasma gas on the surface of the porous carbon powder particles, so as to promote the surface of the porous carbon powder to be completely doped and coated with silicon and carbon, that is, silicon and carbon are dispersed and spread on the surface of the porous carbon powder, which effectively improves the uniformity of doping and coating of the formed silicon-carbon powder.

[0030] The above-mentioned dispersion and adsorption process based on silicon-carbon powder introduces a modifying gas into the porous carbon powder for fluidization treatment, and uses silane compounds and hydrocarbon compounds to perform plasma surface doping and coating on the surface of the porous carbon powder, so that the flow rate of the modifying gas is 10sccm~200sccm, which reduces the agglomeration between the porous carbon powder particles, better ensures the uniform dispersion of the porous carbon powder, and is conducive to the plasma gas being evenly dispersed on the entire surface of the porous carbon powder particles and fully acting. Then, the modifying gas is subjected to plasma treatment, the plasma power supply power is 100W~4000W, and the discharge voltage is 500V~5000V, discharge current 0.2A~3A, temperature 50℃~400℃. On the basis of improving the uniformity of dispersion between porous carbon powder particles, plasma gas is introduced into the porous carbon powder, which effectively improves the uniform distribution of plasma gas on the surface of porous carbon powder particles, and then improves the uniform collision of plasma gas on the surface of porous carbon powder particles, so as to promote the complete doping and coating of silicon and carbon on the surface of porous carbon powder, that is, silicon and carbon are dispersed and spread on the surface of porous carbon powder, which effectively improves the doping and coating uniformity of the formed silicon-carbon powder and improves the electrochemical performance of silicon-carbon powder, anode material of lithium battery.

[0031] In one embodiment, the hydrocarbon compound is at least one of methane, ethane and acetylene. Further, the silane compound is monosilane and / or disilane.

[0032] In one embodiment, before the step of introducing a modifying gas into the porous carbon powder for fluidization treatment and after the step of obtaining the porous carbon powder, the silicon-carbon powder-based dispersion adsorption process further includes the following steps: Inputting an inert gas into the porous carbon powder for fluidization treatment; Further, the inert gas is subjected to plasma treatment for 10 to 20 minutes. Further, the treatment is performed for 15 minutes.

[0033] It can be understood that before the silane compound and the hydrocarbon compound are used to perform plasma surface doping and coating on the porous carbon powder, the porous carbon powder is first fluidized by an inert gas, so that the inert gas is plasma treated on the basis of promoting the dispersion effect between the porous carbon powder particles to form an e -The active particles collide with the surface of the porous carbon powder, which enriches the active sites on the surface of the porous carbon powder and makes the active sites on the surface of the porous carbon powder uniform, so that when the surface of the porous carbon powder is further doped and coated with silane compounds and hydrocarbon compounds, the plasma gas on the surface of the porous carbon powder particles consumes the same amount of collision in the same time, and the plasma consumption and replenishment are coordinated with the flow rate of the modifying gas, so that the plasma gas concentration on the surface of the porous carbon powder particles is the same, avoiding local inconsistency in the concentration of the plasma gas on the surface of the porous carbon powder particles, and achieving the surface of the porous carbon powder particles. The structure of the doping and coating layer with uniform attachment thickness can be evenly dispersed, thereby further improving the doping and coating uniformity of the silicon-carbon powder, and improving the electrochemical performance of the silicon-carbon powder as a negative electrode material for lithium batteries.

[0034] In one embodiment, an inert gas is introduced into the porous carbon powder for fluidization treatment, and the flow rate of the inert gas is 5 sccm-200 sccm, which better ensures uniform dispersion between particles of the porous carbon powder.

[0035] In one embodiment, the inert gas is subjected to plasma treatment, the plasma power is 100W~1500W, the discharge voltage is 500V~5000V, the discharge current is 0.2A~3A, the temperature is 50℃~400℃, and the flow rate of the inert gas is matched, which can better generate e - The active particles are quickly and evenly distributed on the periphery of the porous carbon powder particles, thereby better ensuring the dispersion uniformity of the porous carbon powder and the plasma gas. Further, the inert gas is nitrogen and / or argon.

[0036] In one embodiment, the volume ratio of the silane compound, the hydrocarbon compound and the inert gas is (0.8-1.5): (0.8-1.5): 1. Furthermore, the volume ratio of the silane compound, the hydrocarbon compound and the inert gas is 1:1:1.

[0037] In one embodiment, the particle size distribution of the porous carbon powder is 0.2μm~12μm, and D50 is 1μm~4μm, which meets the particle size requirements of silicon carbon powder of lithium battery negative electrode material, and the flow rate of the modified gas is 10sccm~200sccm, which better ensures the uniform dispersion between the particles of the porous carbon powder.

[0038] In one embodiment, the pore size distribution of the porous carbon powder is 0.2 nm~3.5 nm, and the pore volume is 0.25 cm 3 / g~1cm 3 / g, and the porosity is 60% to 95%. Furthermore, the specific surface area of ​​the porous carbon powder is 1000 m 2 / g~2500m 2 / g. Furthermore, the bulk density of the porous carbon powder is 0.01 cm 3 / g~0.2cm 3 / g, which is conducive to the effective accommodation of silicon and carbon by the porous carbon powder.

[0039] It should be noted that, on the basis of improving the dispersion effect between porous carbon powder particles and improving the dispersion effect of plasma gas on the surface of porous carbon powder, due to the different activities of active sites formed on the surface of porous carbon powder particles, that is, different bonding strengths with silicon and carbon, it is easy to make the local plasma gas on the surface of porous carbon powder particles quickly consumed, and quickly and massively doped and coated with silicon and carbon, there is a problem of poor uniformity of the thickness of the layer structure formed by silicon-carbon doping and coating, thus resulting in poor uniformity of porous carbon powder and silicon-carbon doping and coating. In order to better achieve the uniformity of dispersion of doped and coated silicon and carbon on the surface of porous carbon powder, in one embodiment of the present application, the modified gas is subjected to plasma treatment, which specifically includes the following steps: S310, performing primary plasma treatment on the modifying gas, wherein the flow rate of the modifying gas is 10 sccm~50 sccm; the plasma power supply power is 100 W~500 W, the discharge voltage is 500 V~1500 V, the discharge current is 0.2 A~0.8 A, and the temperature is 50° C.~200° C. It can be understood that the plasma power is 100W~500W, the discharge voltage is 500V~1500V, the discharge current is 0.2A~0.8A, and silicon active particles are mainly produced, and the concentration of silicon active particles is low. The bonding temperature is 50℃~200℃ and the flow rate of the modified gas is 10sccm~50sccm, so that the surface of the porous carbon powder particles is gently and slowly bonded with silicon active particles, which reduces the local uneven distribution of silicon and carbon caused by the rapid and large-scale bonding and attachment of silicon and carbon at the local active sites of the porous carbon powder. In addition, according to the difference in bonding strength of different active sites of the porous carbon powder, the silicon active particles will gradually bond and attach, which reduces the rapid and large-scale local bonding and attachment of silicon and carbon to the surface of the porous carbon powder particles, thereby causing the problem of poor uniformity of silicon-carbon doping and coating formed on the surface of the porous carbon powder particles, and better improves the uniformity of doping and coating of silicon-carbon powder. Further, the processing time is 8min~15min. Further, the processing is realized for 10min.

[0040] S320, performing secondary plasma treatment on the modifying gas, wherein the flow rate of the modifying gas is 100 sccm~200 sccm; the power of the plasma power supply is 2000W~4000W, the discharge voltage is 2500 V~5000V, the discharge current is 1A~3A, and the temperature is 300℃~400℃. It can be understood that after the first-stage plasma treatment, that is, after the silicon doping and coating layers are uniformly formed on the surface of the porous carbon powder particles, the plasma power is then set to 2000W~4000W, the discharge voltage is 2500V~5000V, and the discharge current is 1A~3A. At this time, silicon active particles and carbon active particles are formed at the same time. The flow rate of the modified gas is 100sccm~200sccm and the temperature is 300℃~400℃, so that the silicon active particles and carbon active particles are quickly attached to the surface of the porous carbon powder particles to achieve rapid silicon-carbon doping and coating. Due to the existence of the silicon doping and coating layer structure in the early stage, the silicon active particles and carbon active particles at this time are relatively uniformly attached to the surface of the porous carbon powder particles, which better ensures the uniformity of the doping and coating of the silicon-carbon powder, that is, the uniform thickening of the doping and coating layer structure on the surface of the porous carbon powder particles is quickly achieved. Further, the treatment time is 15min~25min. Furthermore, the processing time is 20 min.

[0041] S330, performing three-stage plasma treatment on the modifying gas, wherein the flow rate of the modifying gas is 50 sccm~100 sccm; the power of the plasma power supply is 500W~2000W, the discharge voltage is 1500 V~2500V, the discharge current is 0.5A~1.5A, and the temperature is 100℃~300℃. It can be understood that, since the secondary plasma treatment improves the efficiency of doping and coating on the surface of porous carbon powder while ensuring the uniformity of doping and coating on the surface of porous carbon powder, the silicon carbon doped and coated on the surface of porous carbon powder is relatively loose, therefore, the plasma power is further made 500W~2000W, the discharge voltage is 1500V~2500V, and the discharge current is 0.5A~1.5A. At this time, silicon active particles and carbon active particles are formed together, and the flow rate of the modified gas is 50sccm~100sccm and the temperature is 100℃~300℃, so that the silicon active particles and carbon active particles are relatively moderately filled on the silicon-carbon doped and coated layer structure on the surface of porous carbon powder, so that a uniform and dense silicon-carbon doped and coated layer structure is formed on the surface of porous carbon powder particles. Further, the treatment time is 10min~20min. Further, the treatment time is 15min.

[0042] The present application also provides a silicon-carbon powder manufacturing device, which is used to implement the silicon-carbon powder dispersion adsorption process described in any of the above embodiments to prepare silicon-carbon powder. Figure 2 , a silicon-carbon powder manufacturing device 10 according to one embodiment includes a powder fluidization system 100, a feeding system 200, a gas source system 300, a plasma discharge system 400, a control system (not shown) and a discharging system 500. The feeding system 200 is connected to the powder fluidization system 100, and the feeding system 200 is used to add porous carbon powder to obtain the porous carbon powder and put it into the powder fluidization system 100. The gas source system 300 is connected to the powder fluidization system 100 to pass the modifying gas into the porous carbon powder for fluidization treatment. The plasma discharge system 400 is connected to the powder fluidization system 100 to perform plasma treatment on the modifying gas. The control system is electrically connected to the gas source system 300 and the plasma discharge system 400, respectively, to control the flow rate of the plasma gas, as well as the plasma power supply power, discharge voltage, discharge current and temperature. The discharging system 500 is in communication with the powder fluidizing system 100 , and the discharging system 500 is used to add porous carbon powder to receive the porous carbon powder output from the powder fluidizing system 100 .

[0043] The above-mentioned silicon-carbon powder manufacturing equipment 10 effectively realizes the implementation of the dispersion adsorption process based on the silicon-carbon powder, ensuring the effective preparation of uniformly doped, mixed and coated silicon-carbon powder.

[0044] The present application also provides a silicon-carbon powder, which is prepared by the silicon-carbon powder production equipment described in any of the above embodiments.

[0045] Compared with the prior art, the present invention has at least the following advantages: The dispersion and adsorption process based on silicon-carbon powder of the present invention introduces a modification gas into the porous carbon powder for fluidization treatment, adopts silane compounds and hydrocarbon compounds to perform plasma surface doping and coating on the surface of the porous carbon powder, promotes the flow rate of the modification gas to be 10sccm~200sccm, reduces the agglomeration between the porous carbon powder particles, better ensures the uniform dispersion of the porous carbon powder, and is conducive to the plasma gas being evenly dispersed on the entire surface of the porous carbon powder particles and fully acting, then, the modification gas is subjected to plasma treatment, the plasma power source power is 100W~4000W, and the discharge voltage is The discharge current is 500V~5000V, the discharge current is 0.2A~3A, and the temperature is 50℃~400℃. On the basis of improving the uniformity of dispersion between porous carbon powder particles, plasma gas is introduced into the porous carbon powder, which effectively improves the uniform distribution of plasma gas on the surface of porous carbon powder particles, thereby improving the uniform collision of plasma gas on the surface of porous carbon powder particles, and promoting the complete doping and coating of silicon and carbon on the surface of porous carbon powder, that is, silicon and carbon are dispersed and spread on the surface of porous carbon powder, which effectively improves the doping and coating uniformity of the formed silicon-carbon powder and improves the electrochemical properties of silicon-carbon powder, anode material of lithium battery.

[0046] Some specific examples are listed below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0047] Example 1 The porous carbon powder (D50 is 2 μm, porosity is 80%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modifying gas is introduced, and the modifying gas includes N2, monosilane and methane (volume ratio 1:1:1); the gas flow rate of the modifying gas is adjusted to 10sccm, the plasma power is turned on, the power is adjusted to 500W, the discharge voltage is 1500V, the discharge current is 0.8A, the temperature is 200℃, and the processing time is 6min; then the gas flow rate of the modifying gas is adjusted to 100sccm, the power is adjusted to 4000W, the discharge voltage is 5000V, the discharge current is 3A, the temperature is 400℃, and the processing time is 15min; then the gas flow rate of the modifying gas is adjusted to 50sccm, the power is adjusted to 2000W, the discharge voltage is 2500V, the discharge current is 1.5A, the temperature is 300℃, and the processing time is 10min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0048] Example 2 The porous carbon powder (D50 is 2 μm, porosity is 80%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modification gas is introduced, and the modification gas includes N2, monosilane and methane (volume ratio 1:1:1); the gas flow rate of the modification gas is adjusted to 20sccm, the plasma power is turned on, the power is adjusted to 200W, the discharge voltage is 800V, the discharge current is 0.4A, the temperature is 100°C, and the treatment time is 10min; then the gas flow rate of the modification gas is adjusted to 140sccm, the power is adjusted to 2800W, the discharge voltage is 3000V, the discharge current is 1.8A, the temperature is 330°C, and the treatment time is 20min; then the gas flow rate of the modification gas is adjusted to 60sccm, the power is adjusted to 900W, the discharge voltage is 1800V, the discharge current is 0.8A, the temperature is 150°C, and the treatment time is 15min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0049] Example 3 The porous carbon powder (D50 is 2 μm, porosity is 80%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modification gas is introduced, and the modification gas includes N2, monosilane and methane (volume ratio 1:1:1); the gas flow rate of the modification gas is adjusted to 35sccm, the plasma power is turned on, the power is adjusted to 350W, the discharge voltage is 1200V, the discharge current is 0.6A, the temperature is 150°C, and the treatment time is 15min; then the gas flow rate of the modification gas is adjusted to 180sccm, the power is adjusted to 3200W, the discharge voltage is 3500V, the discharge current is 2.5A, the temperature is 360°C, and the treatment time is 25min; then the gas flow rate of the modification gas is adjusted to 80sccm, the power is adjusted to 2500W, the discharge voltage is 2200V, the discharge current is 0.2A, the temperature is 220°C, and the treatment time is 20min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0050] Example 4 The porous carbon powder (D50 is 2 μm, porosity is 80%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modification gas is introduced, and the modification gas includes N2, monosilane and methane (volume ratio 1:1:1); the gas flow rate of the modification gas is adjusted to 50sccm, the plasma power is turned on, the power is adjusted to 100W, the discharge voltage is 500V, the discharge current is 0.2A, the temperature is 50℃, and the treatment time is 6min; then the gas flow rate of the modification gas is adjusted to 200sccm, the power is adjusted to 2000W, the discharge voltage is 2500V, the discharge current is 1A, the temperature is 300℃, and the treatment time is 18min; then the gas flow rate of the modification gas is adjusted to 50sccm, the power is adjusted to 500W, the discharge voltage is 1500V, the discharge current is 0.5A, the temperature is 100℃, and the treatment time is 22min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0051] Example 5 The porous carbon powder (D50 is 1 μm, porosity is 60%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modification gas is introduced, and the modification gas includes Ar, monosilane and ethane (volume ratio 1:1:1); the gas flow rate of the modification gas is adjusted to 35sccm, the plasma power is turned on, the power is adjusted to 350W, the discharge voltage is 1200V, the discharge current is 0.6A, the temperature is 150°C, and the treatment time is 8min; then the gas flow rate of the modification gas is adjusted to 180sccm, the power is adjusted to 3200W, the discharge voltage is 3500V, the discharge current is 2.5A, the temperature is 360°C, and the treatment time is 15min; then the gas flow rate of the modification gas is adjusted to 80sccm, the power is adjusted to 2500W, the discharge voltage is 2200V, the discharge current is 0.2A, the temperature is 220°C, and the treatment time is 22min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0052] Example 6 The porous carbon powder (D50 is 4 μm, porosity is 95%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modification gas is introduced, and the modification gas includes Ar, monosilane and acetylene (volume ratio 1:1:1); the gas flow rate of the modification gas is adjusted to 35sccm, the plasma power is turned on, the power is adjusted to 350W, the discharge voltage is 1200V, the discharge current is 0.6A, the temperature is 150°C, and the treatment time is 10min; then the gas flow rate of the modification gas is adjusted to 180sccm, the power is adjusted to 3200W, the discharge voltage is 3500V, the discharge current is 2.5A, the temperature is 360°C, and the treatment time is 15min; then the gas flow rate of the modification gas is adjusted to 80sccm, the power is adjusted to 2500W, the discharge voltage is 2200V, the discharge current is 0.2A, the temperature is 220°C, and the treatment time is 20min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0053] Comparative Example 1 The porous carbon powder (D50 is 2 μm, porosity is 80%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modification gas was introduced, and the modification gas included N2, monosilane and methane (volume ratio 1:1:1); the gas flow rate of the modification gas was adjusted to 100 sccm, the plasma power was turned on, the power was adjusted to 2000 W, the discharge voltage was 2500 V, the discharge current was 1 A, the temperature was 300 ° C, and the treatment time was 45 min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0054] Comparative Example 2 The porous carbon powder (D50 is 2 μm, porosity is 80%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modification gas is introduced, and the modification gas includes N2, monosilane and methane (volume ratio 1:1:1); the gas flow rate of the modification gas is adjusted to 200 sccm, the plasma power supply is turned on, the power is adjusted to 4000 W, the discharge voltage is 5000 V, the discharge current is 3 A, the temperature is 400 ° C, and the treatment time is 30 min; The gas flow rate of the modified gas was adjusted to 60 sccm, the power was adjusted to 600 W, the discharge voltage was 1500 V, the discharge current was 1.0 A, the temperature was 200 ° C, and the treatment time was 15 min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0055] Comparative Example 3 The porous carbon powder (D50 is 2 μm, porosity is 80%) is sucked into the feed bin by negative pressure, the feed valve is opened, and the porous carbon powder is transported to the fluidized reactor by automatic feeding; Turn on the vacuum pump and the outlet valve, introduce inert gas N2, adjust the gas flow rate to 100 sccm, turn on the plasma power supply, adjust the power supply to 1000 W, the discharge voltage to 2500 V, the discharge current to 2 A, the temperature to 250 ° C, and the processing time to 15 min; The modification gas is introduced, and the modification gas includes N2, monosilane and methane (volume ratio 1:1:1); the gas flow rate of the modification gas is adjusted to 200 sccm, and the plasma power is turned on, and the power is adjusted to 4000 W, the discharge voltage is 5000 V, the discharge current is 3 A, the temperature is 400 ° C, and the treatment time is 45 min; Turn off the plasma power supply, replace the modified gas with N2, close the gas outlet valve, open the discharge valve, and transport the silicon-carbon powder to the discharge bin to obtain the finished product.

[0056] The silicon-carbon powders of Examples 1 to 6 and the silicon-carbon powders of Comparative Examples 1 to 3 are used to prepare the negative electrode of a lithium battery to prepare a lithium battery. The specific operation steps are as follows: 1. In a vacuum environment, silicon carbon powder, polyvinylidene fluoride, conductive carbon black and sodium carboxymethyl cellulose were mixed in a mass ratio of 95:2:1.5:1.5, and deionized water was added for homogeneous stirring to obtain a slurry. The slurry was coated on a copper foil with a thickness of 8 μm, dried at 85 ° C for 2 h, then dried at 100 ° C for 12 h, and rolled to a compaction density of 1.65 g / cm 3 Then slice to obtain the negative electrode sheet; 2. Under vacuum, lithium manganese iron phosphate, polyvinylidene fluoride, carbon nanotubes and conductive carbon black were mixed in a mass ratio of 96:2:1:1, and N-methylpyrrolidone was added for homogeneous stirring to obtain a slurry. The slurry was coated on an aluminum foil with a thickness of 12 μm, dried at 100 ° C for 2 h, dried in an oven at 150 ° C for 12 h, and rolled to a compaction density of 4.1 g / cm 3 Then slice to obtain the positive electrode sheet; 3. The diaphragm is a PE non-woven diaphragm with a thickness of 9μm; 4. Under N2 atmosphere, mix PC:EC:PP:PS:LiPF6:FEC in a mass ratio of 12:12:47:4:15:10 and stir evenly to obtain an electrolyte; 5. Encapsulate the negative electrode sheet, positive electrode sheet, separator and electrolyte in an aluminum-plastic film, bake at 80°C for 12 hours, then let it stand, charge with a current of 0.2C to the upper limit of the battery voltage, and then discharge with a current of 0.1C to the battery voltage of 3.8V. The remaining operations and parameters are conventional means and will not be repeated here.

[0057] The prepared lithium battery was subjected to an electrochemical performance test by charging to 4.45V at a constant current of 1.5C, charging to 0.05C at a constant voltage, standing for 10 minutes, discharging to 3.0V at 1C, standing for 10 minutes, and performing this charge and discharge step in a cycle. The results are shown in Table 1: Table 1 Figure 3 This is a transmission electron microscope image of the silicon-carbon powder obtained in Example 2. It can be seen that the thickness of the coating layer formed on the surface of the silicon-carbon powder obtained by the dispersion adsorption process based on silicon-carbon powder of the present application is relatively uniform. Combined with Table 1, it is shown that the silicon-carbon powder obtained by the dispersion adsorption process based on silicon-carbon powder of the present application has good silicon doping uniformity, which makes the thickness growth of the prepared lithium battery significantly slower and the cycle performance is better.

[0058] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A dispersion adsorption process based on silicon-carbon powder, characterized in that: The steps include: obtaining porous carbon powder; A modifying gas is introduced into the porous carbon powder for fluidization treatment, wherein the modifying gas comprises at least a silane compound and a hydrocarbon compound, and the flow rate of the modifying gas is 10 sccm to 200 sccm; The modifying gas is subjected to plasma treatment, and plasma gas is introduced into the porous carbon powder, so that the porous carbon powder and the plasma gas can be evenly dispersed and mixed. The plasma power supply power is 100W~4000W, the discharge voltage is 500V~5000V, the discharge current is 0.2A~3A, and the temperature is 50℃~400℃.

2. The dispersion adsorption process based on silicon-carbon powder according to claim 1, characterized in that: The hydrocarbon compound is at least one of methane, ethane and acetylene; and / or, The silane compound is monosilane and / or disilane.

3. The dispersion adsorption process based on silicon-carbon powder according to claim 1 is characterized in that: The particle size distribution of the porous carbon powder is 0.2 μm to 12 μm, and D50 is 1 μm to 4 μm; and / or, The pore size distribution of the porous carbon powder is 0.2 nm~3.5 nm, and the pore volume is 0.25 cm 3 / g~1cm 3 / g, porosity is 60%~95%; and / or, The specific surface area of ​​the porous carbon powder is 1000 m 2 / g~2500m 2 / g; and / or, The bulk density of the porous carbon powder is 0.01 cm 3 / g~0.2cm 3 / g.

4. The dispersion adsorption process based on silicon-carbon powder according to claim 1, characterized in that: Before the step of introducing a reforming gas into the porous carbon powder for fluidization treatment and after the step of obtaining the porous carbon powder, the silicon-carbon powder-based dispersion adsorption process further includes the following steps: Inputting an inert gas into the porous carbon powder for fluidization treatment; The inert gas is subjected to plasma treatment.

5. The dispersion adsorption process based on silicon-carbon powder according to claim 4, characterized in that: Introducing an inert gas into the porous carbon powder for fluidization treatment, wherein the flow rate of the inert gas is 5 sccm to 200 sccm; and / or, The inert gas is subjected to plasma treatment, the plasma power supply power is 100W~1500W, the discharge voltage is 500V~5000V, the discharge current is 0.2A~3A, and the temperature is 50°C~400°C.

6. The dispersion adsorption process based on silicon-carbon powder according to claim 1, characterized in that: The modifying gas also includes an inert gas.

7. The dispersion adsorption process based on silicon-carbon powder according to claim 4 or 6, characterized in that: The inert gas is nitrogen and / or argon.

8. The dispersion adsorption process based on silicon-carbon powder according to claim 1, characterized in that: Plasma treatment of the modifying gas specifically comprises the following steps: The modifying gas is subjected to a primary plasma treatment, wherein the flow rate of the modifying gas is 10 sccm to 50 sccm; the plasma power supply power is 100 W to 500 W, the discharge voltage is 500 V to 1500 V, the discharge current is 0.2 A to 0.8 A, and the temperature is 50° C. to 200° C.; The modifying gas is subjected to a secondary plasma treatment, wherein the flow rate of the modifying gas is 100 sccm to 200 sccm; the plasma power supply power is 2000 W to 4000 W, the discharge voltage is 2500 V to 5000 V, the discharge current is 1 A to 3 A, and the temperature is 300° C. to 400° C.; The modifying gas is subjected to three-stage plasma treatment, wherein the flow rate of the modifying gas is 50 sccm~100 sccm; the power of the plasma power supply is 500W~2000W, the discharge voltage is 1500 V~2500V, the discharge current is 0.5A~1.5A, and the temperature is 100°C~300°C.

9. A silicon-carbon powder production device, used for implementing the silicon-carbon powder-based dispersion adsorption process according to any one of claims 1 to 8, characterized in that: The silicon-carbon powder production equipment comprises: Powder fluidization system; A feeding system, the feeding system is connected to the powder fluidization system, and the feeding system is used to add porous carbon powder to obtain the porous carbon powder and put it into the powder fluidization system; A gas source system, the gas source system being in communication with the powder fluidization system so as to introduce a modifying gas into the porous carbon powder for fluidization treatment; A plasma discharge system, the plasma discharge system being connected to the powder fluidization system to perform plasma treatment on the modifying gas; A control system, wherein the control system is electrically connected to the powder fluidization system, the gas source system and the plasma discharge system to control the flow rate of the plasma gas, as well as the power of the plasma power supply, the discharge voltage, the discharge current and the temperature; A discharging system is communicated with the powder fluidizing system to receive the porous carbon powder outputted from the powder fluidizing system.

10. A silicon-carbon powder, characterized in that: The silicon-carbon powder is prepared by the silicon-carbon powder production equipment according to claim 9.

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