阅读说明：本技术 生产SiOx的装置及方法 (Production of SiOxApparatus and method of ) 是由 王文 银波 范协诚 秦文军 孙永仕 夏高强 胡颖 于 2019-03-26 设计创作，主要内容包括：本发明公开了一种生产SiO<Sub>x</Sub>的装置及方法,装置包括：反应单元；气体出料单元；收集单元；调温机构；抽真空单元。本发明的方法,能实现SiO<Sub>x</Sub>的连续生产,易实现自动控制,提高生产效率,制得性能良好的SiO<Sub>x</Sub>材料,原料中的难挥发杂质通过反应单元底部残渣去除,通过合理控制反应单元、气体出料单元及收集单元的温度,使大部分易挥发杂质保持气体状态,从收集单元的第一出口排出。本发明装置独特的设计,实现了全流程连续生产,有利于扩大产能,减小设备投入。根据生产特性对细节进行的特殊设计,可以提高产品质量,实现设备长周期稳定运行。由于连续运行省去了启炉加热、停炉冷却等时间和能耗,从而可以提高生产效率,降低能耗。(The invention discloses a method for producing SiO x The device comprises the following steps: a reaction unit; a gas discharge unit; a collection unit; a temperature adjustment mechanism; and a vacuum pumping unit. The method of the invention can realize SiO x The continuous production is easy to realize automatic control, the production efficiency is improved, and the SiO with good performance is prepared x The material, the difficult volatile impurity in the raw materials is got rid of through reaction unit bottom residue, through the temperature of reasonable control reaction unit, gaseous ejection of compact unit and collection unit, makes most volatile impurity keep gaseous state, discharges from the first export of collection unit. The device of the invention has unique design, realizes full-flow continuous production, is beneficial to enlarging the productivity and reducing the equipment investment. The special design of the details according to the production characteristics can improve the product quality and realize the long-period stable operation of the equipment. Because the continuous operation saves time and energy consumption such as furnace starting heating, furnace shutdown cooling and the like, the production efficiency can be improved, and the energy consumption is reduced.)

1. Production of SiO_xThe apparatus of (2), comprising:

a reaction unit for heating the added reaction raw materials of silicon and/or carbon and silicon dioxide step by step to evaporate low boiling point impurities in the raw materials into gaseous impurities step by step, and the raw materials react to generate gaseous SiO_xIn which 1 is<x<2；

The gas ejection of compact unit is connected with the reaction unit, and the gas ejection of compact unit includes: the gas discharging unit is used for conveying and heating the gaseous material flowing out of the reaction unit to keep the gaseous material in a gaseous state;

the collecting unit is connected with the gas discharging unit and is used for receiving the gaseous material flowing out of the gas discharging unit;

the temperature adjusting mechanism is arranged in the collecting unit and used for adjusting the temperature in the collecting unit, and when the collecting unit is cooled, the gaseous SiO enters the collecting unit_xCooling to solid SiO_xThe collecting unit is provided with a first outlet and a second outlet, gaseous impurities are discharged from the first outlet, and solid SiO is arranged_xIs discharged from the second outlet;

and the vacuumizing unit is connected with the first outlet of the collecting unit and is used for vacuumizing the collecting unit.

2. Production of SiO according to claim 1_xThe apparatus of (2), further comprising:

and the filtering unit is arranged at an inlet of the gas discharging unit and is used for filtering and dedusting the gaseous materials flowing to the gas discharging unit from the reaction unit.

3. Production of SiO according to claim 1_xThe apparatus of (2), further comprising:

a feed unit comprising:

the solid feeding unit is connected with the reaction unit and is used for feeding solids to the reaction unit;

and the gas feeding unit is connected with the reaction unit and is used for introducing the non-oxidizing gas into the reaction unit to provide fluidizing gas, and the non-oxidizing gas and the solid feed form a fluidized bed in the reaction unit.

4. Production of SiO according to any of claims 1 to 3_xThe apparatus of (2), further comprising:

and the solid suction unit is connected with the second outlet of the collection unit and is used for sucking the solid in the collection unit.

5. Production of SiO according to claim 4_xThe apparatus of (2), further comprising:

and the storage unit is connected with the solid suction unit and is used for receiving the solid sucked by the solid suction unit.

6. SiO production process according to any of claims 1 to 3 and 5_xThe apparatus of (2), further comprising:

the inlet of the dust removal mechanism is connected with the first outlet of the collection unit, the outlet of the dust removal mechanism is connected with the vacuumizing unit, and the dust removal mechanism is used for removing dust from gas.

7. Use of the device of any one of claims 1-6 for the production of SiO_xThe method is characterized by comprising the following steps:

1) starting a vacuumizing unit for vacuumizing, adding reaction raw materials of silicon and/or carbon and silicon dioxide into the reaction unit, heating through the reaction unit, wherein the heating temperature is lower than the reaction temperature of the raw materials of silicon and/or carbon and silicon dioxide, and evaporating low-boiling-point impurities in the raw materials into gaseous impurities;

2) controlling the gas discharging unit to heat, and keeping the gaseous impurities in a gaseous state;

3) the temperature adjusting mechanism is used for adjusting the collection unit to heat, keeping the gaseous impurities in a gaseous state, and pumping the gaseous impurities out of the first outlet through the vacuumizing unit;

4) heating the reaction unit to the temperature at which the raw material silicon and/or carbon reacts with the silicon dioxide to generate gaseous SiO_xOr gaseous SiO_xAnd carbon monoxide, wherein 1<x<2；

5) Controlling the heating of the gas discharge unit to maintain the gaseous SiO_xIs still in the gaseous state;

6) the temperature of the collecting unit is adjusted by the temperature adjusting mechanism to be reduced, so that the gaseous SiO is_xCooling to solid SiO_xSolid SiO_xIs discharged from the second outlet.

8. Production of SiO according to claim 7_xThe method of (2), characterized in that,

the heating temperature of the reaction unit in the step 1) is 100-1000 ℃;

the heating temperature of the gas discharging unit in the step 2) is 100-1000 ℃;

the heating temperature of the collecting unit in the step 3) is 200-900 ℃.

9. Production of SiO according to claim 7 or 8_xThe method of (2), characterized in that,

the heating temperature of the reaction unit in the step 4) is 1100-2000 ℃;

the heating temperature of the gas discharging unit in the step 5) is 800-1500 ℃;

the temperature of the collecting unit in the step 6) is 100-900 ℃, and the temperature of the collecting unit is lower than that of the gas discharging unit.

10. Production of SiO according to claim 7 or 8_xThe method of (5), wherein the temperature of the collection unit in step 6) is: the temperature gradient from high to low is entered from the inlet of the collecting unit.

Technical Field

The invention belongs to the technical field of lithium ion battery cathode materials, and particularly relates to a method for producing SiO_xThe apparatus and method of (1).

Background

The lithium ion battery has the advantages of high capacity, good safety performance, multiple cycle times, environment-friendly materials and the like, and is widely applied to the fields of smart phones, portable equipment, new energy automobiles and the like in recent years. The lithium ion battery mainly comprises 5 parts of a positive electrode, a negative electrode, electrolyte, a diaphragm, a current collector and the like.

The anode material is a hot spot of current research, and the technical innovation and breakthrough of the anode material are expected to enable the lithium ion battery to have higher energy density and longer service life. The negative electrode material accounts for 25-28% of the total cost of the lithium ion battery. In addition, the theoretical capacity of the traditional graphite cathode material is only 372mAh/g, while the theoretical capacity of the silicon cathode material is 3590 mAh/g. Is considered to be an ideal choice for the cathode of the next generation lithium ion battery. However, in the fully lithium-intercalated state, the volume expansion of the silicon negative electrode can reach 300%, which brings challenges to the service life and safety performance of the lithium battery.

The silicon-carbon composite negative electrode material is one of the methods for solving the volume expansion of silicon materials. The silicon cathode adopts a core-shell structure, and the volume expansion of the silicon cathode is jointly borne by the graphite and the coating layer, so that the pulverization is reduced. At present, enterprises for researching and developing silicon-carbon composite materials at home and abroad comprise Beibei Biibrari, fir science and technology, Jiangxi Zichen, Daliangchang, Beijing nonferrous metal research institute and the like in China, and Japanese Xinyue, Wuyu chemistry, American Aprensis and the like in foreign countries.

The silicon carbide oxide composite material is prepared by uniformly distributing 2-10 nm silicon particles on SiO by chemical vapor deposition₂In the matrix of. The monomer capacity was about 1400 mAh/g. The expansion is low, and the good cycle performance is achieved. The biggest problem is SiO₂The first week of irreversible reaction with lithium, the first effect is generally only about 70%. At present, various large material manufacturers begin to research SiO with better cycle performance_xMaterials, currently commercially available silicon negative electrode materials are also mostly silicon oxide materials.

Hideharu Takezawa et al, Japan Sonaro Ltd_xHigh O content in the material significantly improves cycle performance, but first effect is reduced (e.g., SiO)_xThe capacity retention rate of the 1.02 material can reach 98 percent after 30 times of circulation. SiO 2_xThe first effect of 0.17 is 94%, while SiO_xThe first efficiency of 1.02 is only 53.7%). Junying Zhang et al, the institute of semiconductor, academy of sciences, China, reduced SiO by high-energy ball milling_xThe particle size of the material can improve the cycle and rate performance of the material. The reversible capacity of the material reaches 1416.8mAh/g, the coulombic efficiency is 99.8%, but the first effect is only 63%. At present, a small amount of Li source is added to the positive electrode or the negative electrode to achieve the purpose of improving the first effect. Seung Jong Lee et al, KAIST, Korea institute of science and technology, disperse nano-Si particles in SiO_xIn the particles, the surface is coated with a layer of porous carbon. The reversible capacity reaches 1561.9mAh/g under 0.06C, the first efficiency reaches 80.2%, the 1C cycle is 100 times, and the capacity retention rate can reach 87.9%. Japanese and korean manufacturers developed various adhesives for the problem of volume expansion to reduce the powder falling caused by volume expansion during the circulation process, etc. The mature soft carbon coating process is used for carrying out high-temperature heat treatment on the surface of the silicon monoxide carbon composite raw material, so that the first effect can be improved and the expansion can be relieved. The physical institute and the chemical institute of the Chinese academy of sciences control the oxygen content, regulate and control silicon crystal grains in the silicon monoxide, and optimize the electrochemical performance of the silicon monoxide by compounding with a second phase.

Disclosure of Invention

The technical problem to be solved by the invention is to aim atThe above-mentioned disadvantages existing in the prior art provide a method for producing SiO_xApparatus and method for realizing SiO_xThe continuous production is easy to realize automatic control, the production efficiency is improved, and the SiO with good performance is prepared_xA material.

The technical scheme adopted for solving the technical problem of the invention is to provide a method for producing SiO_xThe apparatus of (1), comprising:

a reaction unit for heating the added reaction raw materials of silicon and/or carbon and silicon dioxide step by step to evaporate low boiling point impurities in the raw materials into gaseous impurities step by step, and the raw materials react to generate gaseous SiO_xIn which 1 is<x<2；

The gas ejection of compact unit is connected with the reaction unit, and the gas ejection of compact unit includes: the gas discharging unit is used for conveying and heating the gaseous material flowing out of the reaction unit to keep the gaseous material in a gaseous state;

the collecting unit is connected with the gas discharging unit and is used for receiving the gaseous material flowing out of the gas discharging unit;

the temperature adjusting mechanism is arranged in the collecting unit and used for adjusting the temperature in the collecting unit, and when the collecting unit is cooled, the gaseous SiO enters the collecting unit_xCooling to solid SiO_xThe collecting unit is provided with a first outlet and a second outlet, gaseous impurities are discharged from the first outlet, and solid SiO is arranged_xIs discharged from the second outlet;

and the vacuumizing unit is connected with the first outlet of the collecting unit and is used for vacuumizing the collecting unit.

Preferably, the SiO is produced by_xThe apparatus of (2), further comprising:

and the filtering unit is arranged at an inlet of the gas discharging unit and is used for filtering and dedusting the gaseous materials flowing to the gas discharging unit from the reaction unit.

Preferably, the SiO is produced by_xThe apparatus of (2), further comprising:

a feed unit comprising:

the solid feeding unit is connected with the reaction unit and is used for feeding solids to the reaction unit;

and the gas feeding unit is connected with the reaction unit and is used for introducing the non-oxidizing gas into the reaction unit to provide fluidizing gas, and the non-oxidizing gas and the solid feed form a fluidized bed in the reaction unit.

Preferably, the SiO is produced by_xThe apparatus of (2), further comprising:

and the solid suction unit is connected with the second outlet of the collection unit and is used for sucking the solid in the collection unit.

Preferably, the SiO is produced by_xThe apparatus of (2), further comprising:

and the storage unit is connected with the solid suction unit and is used for receiving the solid sucked by the solid suction unit.

Preferably, the solids extraction unit is a venturi mechanism.

Preferably, the SiO is produced by_xThe apparatus of (2), further comprising:

the inlet of the dust removal mechanism is connected with the first outlet of the collection unit, the outlet of the dust removal mechanism is connected with the vacuumizing unit, and the dust removal mechanism is used for removing dust from gas.

The invention also provides the SiO production_xThe use method of the device comprises the following steps:

1) starting a vacuumizing unit for vacuumizing, adding reaction raw materials of silicon and/or carbon and silicon dioxide into the reaction unit, heating through the reaction unit, wherein the heating temperature is lower than the reaction temperature of the raw materials of silicon and/or carbon and silicon dioxide, and evaporating low-boiling-point impurities in the raw materials into gaseous impurities;

2) controlling the gas discharging unit to heat, and keeping the gaseous impurities in a gaseous state;

3) the temperature adjusting mechanism is used for adjusting the collection unit to heat, keeping the gaseous impurities in a gaseous state, and pumping the gaseous impurities out of the first outlet through the vacuumizing unit;

4) heating the reaction unit to raise the temperature of the raw material siliconOr the temperature at which carbon reacts with silicon dioxide, the starting material silicon and/or carbon reacting with silicon dioxide to form gaseous SiO_xOr gaseous SiO_xAnd carbon monoxide, wherein 1<x<2；

5) Controlling the heating of the gas discharge unit to maintain the gaseous SiO_xIs still in the gaseous state;

6) the temperature of the collecting unit is adjusted by the temperature adjusting mechanism to be reduced, so that the gaseous SiO is_xCooling to solid SiO_xSolid SiO_xIs discharged from the second outlet.

Preferably, the heating temperature of the reaction unit in the step 1) is 100-1000 ℃; vacuumizing to 100-5000 Pa.

The heating temperature of the gas discharging unit in the step 2) is 100-1000 ℃;

the heating temperature of the collecting unit in the step 3) is 200-900 ℃.

Preferably, the heating temperature of the reaction unit in the step 4) is 1100-2000 ℃;

the heating temperature of the gas discharging unit in the step 5) is 800-1500 ℃;

the temperature of the collecting unit in the step 6) is 100-900 ℃, and the temperature of the collecting unit is lower than that of the gas discharging unit.

Preferably, the temperature of the collecting unit in the step 6) is: the temperature gradient from high to low is entered from the inlet of the collecting unit.

Preferably, the vacuumizing unit in the step 1) is vacuumized to 100-5000 Pa, the particle size of the reaction raw material silicon and/or carbon is 50-300 meshes, and the particle size of the silicon dioxide is 50-300 meshes.

The invention provides a method for producing SiO_xApparatus and method for realizing SiO_xThe continuous production is easy to realize automatic control, the production efficiency is improved, and the SiO with good performance is prepared_xThe material, the difficult volatile impurity in the raw materials is got rid of through reaction unit bottom residue, through the temperature of reasonable control reaction unit, gaseous discharging unit and collection unit, makes most volatile impurity (low boiling point impurity) keep gaseous state, discharges from the first export of collection unit. The device of the invention is independentThe special design realizes the full-flow continuous production, is beneficial to expanding the productivity, reducing the equipment investment and realizing the automation. Meanwhile, the special design of the details is carried out according to the production characteristics, so that the product quality can be improved, and the long-period stable operation of the equipment is realized. In addition, the continuous operation saves time and energy consumption for starting the furnace, stopping the furnace, cooling and the like, thereby improving the production efficiency and reducing the energy consumption.

Drawings

FIG. 1 is a diagram showing SiO production in example 2 of the present invention_xThe structural schematic diagram of the device of (1).

In the figure: 1-a reaction unit; 2-a gas discharge unit; 3-a collection unit; 4-a first outlet; 5-a second outlet; 6-vacuumizing unit; 7-an inlet of the collection unit; 8-a filtration unit; 9-a solid feed unit; 10-a storage bin; 11-a screw conveyor; 12-a gas feed unit; 13-a solids extraction unit; 14-a storage unit; 15-a cyclone separator; 16-bag dust collector; 17-a third outlet; 18-fourth outlet.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Reference will now be made in detail to embodiments of the present patent, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present patent and are not to be construed as limiting the present patent.