Preparation device and method of a silicon monoxide negative electrode material

Abstract

The application provides a preparation device and a preparation method of a silicon monoxide negative electrode material. The preparation device comprises, in sequence along a material flow direction, a vacuum heating assembly, a heating deposition assembly, a crushing and screening assembly, a carbon-coated heating assembly and a pre-lithium assembly. The heating temperature of the vacuum heating assembly is higher than the heating temperature of the heating deposition assembly. The preparation device of the silicon monoxide negative electrode material provided by the application is based on high-temperature vacuum evaporation in the vacuum heating assembly and the heating deposition assembly, crushing and screening in the crushing and screening assembly, chemical vapor deposition in the carbon-coated heating assembly and gas-phase pre-lithium in the pre-lithium assembly. The silicon monoxide negative electrode material with excellent performance is prepared, and a process system solution for preparing the silicon monoxide negative electrode material can be formed by the preparation device.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of negative electrode materials, and particularly relates to a preparation device and a preparation method of a silicon monoxide negative electrode material. BACKGROUND

[0002] With the rapid development of consumer electronics and electric vehicles, lithium ion battery technology has made great progress. High specific energy lithium ion batteries are the focus of development. As one of the negative electrode materials that determines the energy density of lithium ion batteries, the current commercial negative electrode material is mainly artificial / natural graphite. However, the theoretical specific capacity of graphite is 372 mAh / g, which cannot meet the needs of high energy density batteries. The theoretical specific capacity of silicon negative electrode material is 4200 mAh / g, which is more than 10 times that of graphite negative electrode. Moreover, there is no risk of lithium extraction, and the safety is better than that of graphite negative electrode material. In addition, silicon is abundant in reserves and low in cost, and is the most potential next-generation lithium battery negative electrode material. However, silicon has a huge volume change during charging and discharging, and the electronic conductivity is extremely poor, which seriously affects the cycle performance and large current charging and discharging capacity of silicon-based negative electrodes.

[0003] Silicon-based materials are currently the most potential negative electrode materials for lithium ion batteries, and their main advantage is high specific capacity. The theoretical specific capacity of silicon single material is as high as 4200 mAh / g, and the theoretical specific capacity of silicon monoxide material is also as high as 2100 mAh / g, which is much higher than that of carbon negative electrode materials. However, the existing technology mainly focuses on the coating modification of silicon monoxide, and there is no report on the standardized preparation process of silicon monoxide negative electrode material from the perspective of industrialization.

[0004] CN114824241A discloses a device and method for liquid phase pre-lithiation treatment of silicon monoxide negative electrode material. The device includes a solvent kettle for dissolving lithium source in organic solvent, a mixing kettle for mixing silicon monoxide negative electrode material and lithium source, and a solvent recovery kettle for recovering organic solvent. The device can effectively solve the safety hazard problem caused by the volatilization of organic solvent during the liquid phase pretreatment process, and can realize the recovery and reuse of organic solvent, significantly reduce the production cost, and has good economic benefit and industrial application prospect. However, the device for liquid phase pre-lithiation treatment of silicon monoxide negative electrode material can only be used for pre-lithiation of silicon monoxide negative electrode material, and cannot realize the standardized preparation of silicon monoxide negative electrode material.

[0005] The existing preparation devices for silicon monoxide negative electrode material have certain defects, and cannot realize the standardized preparation of silicon monoxide negative electrode material. Therefore, it is very important to develop and design a new preparation device and preparation method for silicon monoxide negative electrode material. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a preparation device for silicon monoxide negative electrode material and a preparation method thereof, the preparation device for silicon monoxide negative electrode material provided by the present application is based on high-temperature vacuum evaporation in a vacuum heating assembly and a heating deposition assembly, crushing and screening in a crushing and screening assembly, chemical vapor deposition in a carbon coating heating assembly, and gas-phase prelithiation in a prelithiation assembly, and a silicon monoxide negative electrode material with excellent performance is prepared, and a process system solution for preparing the silicon monoxide negative electrode material can be formed by the preparation device.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a preparation device for silicon monoxide negative electrode material, which comprises, in sequence along the material flow direction, a vacuum heating assembly, a heating deposition assembly, a crushing and screening assembly, a carbon coating heating assembly, and a prelithiation assembly.

[0009] The heating temperature of the vacuum heating assembly is higher than the heating temperature of the heating deposition assembly.

[0010] The preparation device provided by the present application takes into account the connection and matching between the process sections, can better realize the transmission of materials between the process sections, improve the process efficiency and productivity, reduce material loss, prolong the use time of the equipment in each process section, and reduce the cost of the whole cycle service life.

[0011] The preparation device for silicon monoxide negative electrode material provided by the present application is based on high-temperature vacuum evaporation in a vacuum heating assembly and a heating deposition assembly, crushing and screening in a crushing and screening assembly, chemical vapor deposition in a carbon coating heating assembly, and gas-phase prelithiation in a prelithiation assembly, and a silicon monoxide negative electrode material with excellent performance is prepared, and a process system solution for preparing the silicon monoxide negative electrode material can be formed by the preparation device.

[0012] Preferably, the preparation device further comprises a stock bin arranged before the vacuum heating assembly along the material flow direction.

[0013] Preferably, a first valve is arranged on the connecting pipeline between the stock bin and the vacuum heating assembly.

[0014] Preferably, the vacuum heating assembly comprises a vacuum reaction chamber and a first heating furnace arranged outside the periphery of the vacuum reaction chamber.

[0015] Preferably, the preparation device further comprises a conveyor arranged between the vacuum heating assembly and the heating deposition assembly along the material flow direction.

[0016] Preferably, the heating deposition assembly comprises a deposition reaction chamber and a second heating furnace arranged at the periphery of the deposition reaction chamber.

[0017] Preferably, the heating temperature of the first heating furnace is higher than the heating temperature of the second heating furnace.

[0018] Preferably, a second valve is arranged on the connecting pipeline between the heating deposition assembly and the crushing and screening assembly.

[0019] Preferably, the crushing and screening assembly comprises a crusher and a screener connected with each other, the crusher is connected with the heating deposition assembly, and the screener is connected with the carbon-coating heating assembly.

[0020] Preferably, the crusher is provided with a crusher outlet, a first inlet and a second inlet, and the screener is provided with a screener inlet, a first outlet and a second outlet.

[0021] The crusher outlet is in communication with the screener inlet, the first inlet is in communication with the outlet of the heating deposition assembly, the first outlet is in communication with the inlet of the carbon-coating heating assembly, and the second inlet is in communication with the second outlet.

[0022] Preferably, the crusher comprises an air flow crusher.

[0023] Preferably, a third valve is arranged on the connecting pipeline between the crushing and screening assembly and the carbon-coating heating assembly.

[0024] Preferably, the carbon-coating heating assembly comprises a carbon-coating reaction chamber and a third heating furnace arranged at the periphery of the carbon-coating reaction chamber.

[0025] Preferably, the carbon-coating reaction chamber comprises a fluidized bed coating reaction chamber.

[0026] The fluidized bed coating reaction chamber in the present application has the following advantages: (1) gas and solid are fully mixed, the heat and mass transfer coefficients between the two phases are high, the time can be shortened, and the production capacity of the equipment can be improved; (2) the equipment has high production intensity and can be operated continuously; (3) after the solid particles are fluidized, they have the characteristics of fluid, so the operation is convenient and easy to control, and the labor intensity can be reduced; (4) the equipment is simple and easy to maintain and manufacture; (5) the operation safety is good.

[0027] Preferably, the fluidized bed coating reaction chamber is a vertical fluidized bed.

[0028] The carbon coating is completed in the vertical fluidized bed in the application, and high-performance silicon negative electrode material can be continuously produced, and the production cycle is shortened; the fluidized bed chemical vapor deposition method adopted in the application is beneficial to improve the reaction efficiency and fully react due to the high heat and mass transfer characteristics, and gas molecules diffuse into the pores, defects and cracks of the raw material particles to form an effective filling and coating structure.

[0029] Preferably, the bottom of the fluidized bed coating reaction chamber is provided with a fluidizing gas inlet pipe and a carbon source gas inlet pipe.

[0030] Preferably, the fluidizing gas inlet pipe and the carbon source gas inlet pipe are each provided with a flow control valve.

[0031] Preferably, the carbon coating reaction chamber is connected with an exhaust gas collector.

[0032] Preferably, a fourth valve is arranged on the connecting pipeline between the carbon coating heating assembly and the pre-lithium assembly.

[0033] Preferably, the pre-lithium assembly comprises a pre-lithium reaction chamber and a fourth heating furnace arranged outside the periphery of the pre-lithium reaction chamber.

[0034] Preferably, the preparation device further comprises a product collector arranged after the pre-lithium assembly along the material flow direction.

[0035] In a second aspect, the application provides a preparation method using the preparation device of the first aspect, and the preparation method comprises:

[0036] After the silicon monoxide raw material is vacuum heated in the vacuum heating assembly to form steam, the obtained steam enters the heated deposition assembly to be deposited to obtain blocky silicon monoxide, the blocky silicon monoxide enters the crushing and screening assembly to be crushed and screened at least once, and then enters the coating heating assembly to be subjected to fluidization treatment and carbon coating treatment to obtain powder particles, and the obtained powder particles enter the pre-lithium assembly to be subjected to pre-lithium treatment to obtain silicon monoxide negative electrode material.

[0037] The preparation method of the application realizes the continuous performance of the blocky production, crushing and screening, carbon coating and pre-lithium treatment of silicon monoxide, shortens the preparation cycle of silicon negative electrode material, and has the advantages of simple preparation process, strong operability, safety and reliability, environmental friendliness and low cost.

[0038] As a preferred technical solution of the preparation method of the application, the preparation method comprises the following steps:

[0039] (1) opening the first valve, closing the second valve, the third valve and the fourth valve, the silicon monoxide raw material in the silo enters the vacuum reaction chamber, after closing the first valve, the vacuum reaction chamber is subjected to vacuum treatment, the first heating furnace is opened to make the temperature in the vacuum reaction chamber reach the first set temperature and keep warm, the second heating furnace is opened to make the temperature in the deposition reaction chamber reach the second set temperature and keep warm, the third heating furnace is opened to make the temperature in the carbon-coated reaction chamber reach the third set temperature and keep warm, the fourth heating furnace is opened to make the temperature in the pre-lithium reaction chamber reach the fourth set temperature and keep warm, the silicon monoxide raw material is subjected to vacuum heating in the vacuum reaction chamber to form steam;

[0040] (2) the steam obtained in step (1) is transported to the deposition reaction chamber by the conveyor, and after heating and deposition in the deposition reaction chamber, blocky silicon monoxide is obtained;

[0041] (3) opening the second valve, the blocky silicon monoxide obtained in step (2) enters the jet mill, then closing the second valve, the blocky silicon monoxide is subjected to crushing treatment in the jet mill and then enters the sifter, after sifting, the coarse particles enter the jet mill for secondary crushing treatment and then enter the sifter, and after sifting, powder silicon monoxide with a set particle size is obtained;

[0042] (4) opening the third valve, the powder silicon monoxide obtained in step (3) enters the fluidized bed coating reaction chamber, after closing the third valve, fluidizing gas is introduced into the fluidized bed coating reaction chamber to make the powder silicon monoxide undergo fluidization treatment, and carbon source gas is introduced for carbon coating treatment to obtain powder particles, and the tail gas generated enters the tail gas collector;

[0043] (5) opening the fourth valve, the powder particles obtained in step (4) enter the pre-lithium reaction chamber, and the silicon monoxide negative electrode material obtained after pre-lithium treatment enters the product collector.

[0044] Preferably, the vacuum degree in the vacuum reaction chamber after the vacuum treatment is 0.01-100 Pa, for example, it can be 0.01 Pa, 0.05 Pa, 0.1 Pa, 0.5 Pa, 1 Pa, 5 Pa, 10 Pa, 50 Pa or 100 Pa, but not limited to the listed values, other values not listed in this range are also applicable.

[0045] Preferably, the first set temperature in step (1) is 1100-1600℃, for example, it can be 1100℃, 1150℃, 1200℃, 1250℃, 1300℃, 1350℃, 1400℃, 1450℃, 1500℃, 1550℃ or 1600℃, but not limited to the listed values, other values not listed in this range are also applicable.

[0046] Preferably, the second set temperature in step (1) is 500-900 °C, for example, it can be 500 °C, 600 °C, 700 °C, 800 °C or 900 °C, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0047] Preferably, the third set temperature in step (1) is 600-1000 °C, for example, it can be 600 °C, 700 °C, 800 °C, 900 °C or 1000 °C, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0048] Preferably, the fourth set temperature in step (1) is 500-900 °C, for example, it can be 500 °C, 600 °C, 700 °C, 800 °C or 900 °C, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0049] Preferably, the time of vacuum heating in step (1) is 4-24 h, for example, it can be 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h or 24 h, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0050] Preferably, the time of heating deposition in step (2) is 2-8 h, for example, it can be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h or 8 h, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0051] Preferably, the set particle size in step (3) is 1-20 μm, for example, it can be 1 μm, 3 μm, 5 μm, 7 μm, 9 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm or 20 μm, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0052] Preferably, the total time of fluidization treatment and carbon-coated treatment in step (4) is 0.5-2 h, for example, it can be 0.5 h, 0.7 h, 0.9 h, 1 h, 1.2 h, 1.4 h, 1.6 h, 1.8 h or 2 h, but not only limited to the listed values, other values not listed in the range of values are also applicable.

[0053] Preferably, the fluidization gas in step (4) comprises nitrogen and / or argon.

[0054] Preferably, the carbon source gas in step (4) comprises any one or a combination of at least two of methane, ethylene, acetylene or propylene, and typical but non-limiting combinations include a combination of methane and ethylene, a combination of ethylene and acetylene, a combination of acetylene and propylene, or a combination of methane, ethylene and acetylene.

[0055] Preferably, the carbon source gas in step (4) accounts for 5-30% of the total volume of the carbon source gas and the fluidization gas, for example, can be 5%, 7%, 9%, 10%, 15%, 20%, 25% or 30%, but is not limited to the listed values, and other values not listed within the range are also applicable.

[0056] Preferably, the total gas velocity of the fluidization gas and the carbon source gas introduced in step (4) is 0.1-2 m / s, for example, can be 0.1 m / s, 0.2 m / s, 0.3 m / s, 0.5 m / s, 1 m / s, 1.5 m / s or 2 m / s, but is not limited to the listed values, and other values not listed within the range are also applicable.

[0057] Preferably, the pre-lithiation treatment in step (5) is performed for 1-5 h, for example, can be 1 h, 2 h, 3 h, 4 h or 5 h, but is not limited to the listed values, and other values not listed within the range are also applicable.

[0058] Preferably, the pre-lithiation treatment in step (5) comprises vaporizing a lithium source and performing a lithiation reaction on the surface of the powder particles obtained in step (4).

[0059] The pre-lithiation treatment of the present application is a gas-phase pre-lithiation, which can efficiently improve the initial coulombic efficiency by vaporizing a lithium source and performing a lithiation reaction on the surface of the silicon monoxide. Compared with the existing mechanical mixing pre-lithiation technology, the gas-phase pre-lithiation has the advantages of reducing the use amount of expensive pre-lithiation agent, reducing costs, uniform and efficient pre-lithiation, and further improving the initial coulombic efficiency.

[0060] Preferably, the lithium source comprises any one or a combination of at least two of lithium carbonate, lithium hydroxide or lithium oxide, and typical but non-limiting combinations include a combination of lithium carbonate and lithium hydroxide, a combination of lithium hydroxide and lithium oxide, or a combination of lithium carbonate, lithium hydroxide and lithium oxide.

[0061] Compared with the prior art, the present application has the following beneficial effects:

[0062] (1) The preparation device of the silicon monoxide negative electrode material provided by the present application is based on high-temperature vacuum evaporation in the vacuum heating assembly and the heating deposition assembly, crushing and screening in the crushing and screening assembly, chemical vapor deposition in the carbon coating heating assembly, and gas phase prelithiation in the prelithiation assembly, so that the silicon monoxide negative electrode material with excellent performance is prepared, and the process system solution of the preparation of the silicon monoxide negative electrode material is formed by the preparation device.

[0063] (2) The preparation method realizes the continuous implementation of the block production, crushing and screening, carbon coating, and prelithiation treatment of the silicon monoxide, shortens the preparation period of the silicon negative electrode material, and has the advantages of simple preparation process, strong operability, safety and reliability, environmental friendliness, and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0064] Figure 1 It is a structure schematic view of the preparation device of the silicon monoxide negative electrode material in one specific embodiment of the present application.

[0065] Among them, 1 is a stock bin; 2 is a first valve; 3 is a first heating furnace; 4 is a vacuum reaction chamber; 5 is a conveyor; 6 is a second heating furnace; 7 is a deposition reaction chamber; 8 is a second valve; 9 is an airflow crusher; 10 is a sifter; 11 is a third valve; 12 is a third heating furnace; 13 is a fluidized bed coating reaction chamber; 14 is a tail gas collector; 15 is a fourth valve; 16 is a fourth heating furnace; 17 is a prelithiation reaction chamber; 18 is a product collector. DETAILED DESCRIPTION

[0066] It should be understood that, in the description of the present application, the orientation or positional relationship indicated by the terms "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second", and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0067] It should be noted that in the description of the present application, unless otherwise explicitly specified and limited, the terms "arrangement", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0068] It should be understood by those skilled in the art that the present application necessarily includes necessary pipelines, conventional valves and general pump equipment for realizing the process integrity, but the above content is not the main innovation point of the present application, those skilled in the art can add layout by themselves based on process flow and equipment structure selection, and the present application does not make special requirements and specific limitations.

[0069] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application, and should not be regarded as specific limitations of the present application.

[0070] In one specific embodiment, as shown in Figure 1 The present application provides a preparation device for silicon monoxide negative electrode material, which comprises a vacuum heating assembly, a heating deposition assembly, a crushing and screening assembly, a carbon coating heating assembly and a pre-lithium assembly connected in sequence along the material flow direction.

[0071] The heating temperature of the vacuum heating assembly is higher than the heating temperature of the heating deposition assembly.

[0072] The preparation device provided by the present application takes into account the connection and matching between each process section, can better realize the transmission of materials between process sections, improve process efficiency and productivity, reduce material loss, prolong the use time of each process section equipment, and reduce the life cycle cost.

[0073] The preparation device for silicon monoxide negative electrode material provided by the present application is based on high-temperature vacuum evaporation in the vacuum heating assembly and the heating deposition assembly, crushing and screening in the crushing and screening assembly, chemical vapor deposition in the carbon coating heating assembly, and gas phase pre-lithium in the pre-lithium assembly, and a silicon monoxide negative electrode material with excellent performance is prepared. The process system solution for preparing the silicon monoxide negative electrode material can be formed by the preparation device.

[0074] Further, the preparation device further comprises a stock bin 1 arranged before the vacuum heating assembly along the material flow direction.

[0075] Further, a first valve 2 is arranged on the connecting pipeline between the stock bin 1 and the vacuum heating assembly.

[0076] Further, the vacuum heating assembly comprises a vacuum reaction chamber 4 and a first heating furnace 3 arranged at the periphery of the vacuum reaction chamber 4.

[0077] Further, the preparation device further comprises a conveyor 5 arranged between the vacuum heating assembly and the heating deposition assembly along the material flow direction.

[0078] Further, the heating deposition assembly comprises a deposition reaction chamber 7 and a second heating furnace 6 arranged at the periphery of the deposition reaction chamber 7.

[0079] Further, the heating temperature of the first heating furnace 3 is higher than the heating temperature of the second heating furnace 6.

[0080] Further, a second valve 8 is arranged on the connecting pipeline between the heating deposition assembly and the crushing and screening assembly.

[0081] Further, the crushing and screening assembly comprises a crusher and a screener 10 connected to each other, the crusher is connected to the heating deposition assembly, and the screener 10 is connected to the carbon-coated heating assembly.

[0082] Further, the crusher is provided with a crusher outlet, a first inlet and a second inlet, and the screener 10 is provided with a screener 10 inlet, a first outlet and a second outlet.

[0083] The crusher outlet and the screener 10 inlet are in communication, the first inlet and the outlet of the heating deposition assembly are in communication, the first outlet and the inlet of the carbon-coated heating assembly are in communication, and the second inlet and the second outlet are in communication.

[0084] Further, the crusher comprises an airflow crusher 9.

[0085] Further, a third valve 11 is arranged on the connecting pipeline between the crushing and screening assembly and the carbon-coated heating assembly.

[0086] Further, the carbon-coated heating assembly comprises a carbon-coated reaction chamber and a third heating furnace 12 arranged at the periphery of the carbon-coated reaction chamber.

[0087] Further, the carbon-coated reaction chamber comprises a fluidized bed coating reaction chamber 13.

[0088] The fluidized bed coating reaction chamber 13 in the application has the following advantages: (1) gas-solid is fully mixed, the heat and mass transfer coefficient between the two phases is high, the time can be shortened, and the production capacity of the equipment can be improved; (2) the equipment has high production intensity and can be operated continuously; (3) after the solid particles are fluidized, they have the characteristics of fluid, so the operation is convenient and easy to control, and the labor intensity can be reduced; (4) the equipment is simple and easy to maintain and manufacture; (5) the operation is safe.

[0089] Further, the fluidized bed coating reaction chamber 13 is a vertical fluidized bed.

[0090] In the application, the carbon coating is completed in a vertical fluidized bed, which can continuously produce high-performance silicon negative electrode materials and shorten the production cycle; the fluidized bed chemical vapor deposition method used in the application has high heat and mass transfer characteristics, which is beneficial to improve the reaction efficiency and fully react, so that gas molecules diffuse into the pores, defects and cracks of the raw material particles and form an effective filling and coating structure.

[0091] Further, the bottom of the fluidized bed coating reaction chamber 13 is provided with a fluidizing gas inlet pipe and a carbon source gas inlet pipe.

[0092] Further, the fluidizing gas inlet pipe and the carbon source gas inlet pipe are each provided with a flow control valve.

[0093] Further, the carbon coating reaction chamber is connected with a tail gas collector 14.

[0094] Further, a fourth valve 15 is arranged on the connecting pipeline between the carbon coating heating assembly and the pre-lithium assembly.

[0095] Further, the pre-lithium assembly includes a pre-lithium reaction chamber 17 and a fourth heating furnace 16 arranged outside the periphery of the pre-lithium reaction chamber 17.

[0096] Further, the preparation device further includes a product collector 18 arranged after the pre-lithium assembly along the material flow direction.

[0097] Example 1

[0098] The present embodiment provides a preparation method of the above preparation device, which includes the following steps:

[0099] (1) opening the first valve 2, closing the second valve 8, the third valve 11 and the fourth valve 15, the silicon monoxide raw material in the bin 1 enters the vacuum reaction chamber 4, after closing the first valve 2, vacuumizing the vacuum reaction chamber 4 until the vacuum degree in the vacuum reaction chamber 4 is 10 Pa, opening the first heating furnace 3 to make the temperature in the vacuum reaction chamber 4 reach 1400℃ and keep warm, opening the second heating furnace 6 to make the temperature in the deposition reaction chamber 7 reach 600℃ and keep warm, opening the third heating furnace 12 to make the temperature in the carbon-coated reaction chamber reach 800℃ and keep warm, opening the fourth heating furnace 16 to make the temperature in the pre-lithium reaction chamber 17 reach 600℃ and keep warm, the silicon monoxide raw material in the vacuum reaction chamber 4 is vacuum heated for 10 h to form steam;

[0100] (2) the steam obtained in step (1) is transported to the deposition reaction chamber 7 by the conveyor 5, and after being heated and deposited in the deposition reaction chamber 7 for 4 h, blocky silicon monoxide is obtained;

[0101] (3) opening the second valve 8, after the blocky silicon monoxide obtained in step (2) enters the jet mill 9, closing the second valve 8, the blocky silicon monoxide is crushed in the jet mill 9 and then enters the sifter 10, after being sieved in the sifter 10, the coarse particles enter the jet mill 9 for secondary crushing and then enter the sifter 10, and after being sieved, powder silicon monoxide with a particle size of 5 μm is obtained;

[0102] (4) opening the third valve 11, the powder silicon monoxide obtained in step (3) enters the fluidized bed coating reaction chamber 13, after closing the third valve 11, nitrogen is introduced into the fluidized bed coating reaction chamber 13 to make the powder silicon monoxide fluidized, and acetylene is introduced for carbon coating treatment to obtain powder particles, the total gas velocity of nitrogen and acetylene is 1 m / s, the volume fraction of acetylene in the total volume of acetylene and nitrogen is 10%, the total time of fluidization treatment and carbon coating treatment is 1 h, and the tail gas is introduced into the tail gas collector 14;

[0103] (5) opening the fourth valve 15, the powder particles obtained in step (4) enter the pre-lithium reaction chamber 17, lithium hydroxide vapor is evaporated to perform lithiumation reaction on the surface of the powder particles obtained in step (4) for 2 h, and the obtained silicon monoxide negative electrode material enters the product collector 18.

[0104] Example 2

[0105] The present embodiment provides a preparation method of the above preparation device, which comprises the following steps:

[0106] (1) opening the first valve 2, closing the second valve 8, the third valve 11 and the fourth valve 15, the silicon monoxide raw material in the bin 1 enters the vacuum reaction chamber 4, after closing the first valve 2, the vacuum reaction chamber 4 is subjected to vacuumizing treatment until the vacuum degree in the vacuum reaction chamber 4 is 100 Pa, the first heating furnace 3 is opened to make the temperature in the vacuum reaction chamber 4 reach 1600℃ and keep warm, the second heating furnace 6 is opened to make the temperature in the deposition reaction chamber 7 reach 900℃ and keep warm, the third heating furnace 12 is opened to make the temperature in the carbon-coated reaction chamber reach 1000℃ and keep warm, the fourth heating furnace 16 is opened to make the temperature in the pre-lithium reaction chamber 17 reach 900℃ and keep warm, the silicon monoxide raw material is subjected to vacuum heating in the vacuum reaction chamber 4 for 24 h to form steam;

[0107] (2) the steam obtained in step (1) is transported to the deposition reaction chamber 7 by the conveyor 5, and is subjected to heating deposition in the deposition reaction chamber 7 for 8 h to obtain block silicon monoxide;

[0108] (3) opening the second valve 8, the block silicon monoxide obtained in step (2) enters the jet mill 9, then closing the second valve 8, the block silicon monoxide is subjected to crushing treatment in the jet mill 9 and then enters the sifter 10, after sifting in the sifter 10, the coarse particles enter the jet mill 9 for secondary crushing treatment and then enter the sifter 10, and after sifting, powder silicon monoxide with a particle size of 5 μm is obtained;

[0109] (4) opening the third valve 11, the powder silicon monoxide obtained in step (3) enters the fluidized bed coating reaction chamber 13, after closing the third valve 11, nitrogen is introduced into the fluidized bed coating reaction chamber 13 to make the powder silicon monoxide subjected to fluidization treatment, and acetylene is introduced to make the powder silicon monoxide subjected to carbon coating treatment to obtain powder particles, the total gas velocity of the nitrogen and the acetylene is 1 m / s, the acetylene accounts for 10% of the total volume of the acetylene and the nitrogen, the total time of the fluidization treatment and the carbon coating treatment is 1 h, and the tail gas generated is introduced into the tail gas collector 14;

[0110] (5) opening the fourth valve 15, the powder particles obtained in step (4) enter the pre-lithium reaction chamber 17, lithium hydroxide is vaporized and subjected to lithiation reaction on the surface of the powder particles obtained in step (4) for 5 h to obtain silicon monoxide negative electrode material which enters the product collector 18.

[0111] Example 3

[0112] The present embodiment provides a preparation method of the above preparation device, the preparation method comprising the following steps:

[0113] (1) opening the first valve 2, closing the second valve 8, the third valve 11 and the fourth valve 15, the silicon monoxide raw material in the bin 1 enters the vacuum reaction chamber 4, after closing the first valve 2, vacuumizing the vacuum reaction chamber 4 until the vacuum degree in the vacuum reaction chamber 4 is 0.01 Pa, opening the first heating furnace 3 to make the temperature in the vacuum reaction chamber 4 reach 1100℃ and keep warm, opening the second heating furnace 6 to make the temperature in the deposition reaction chamber 7 reach 500℃ and keep warm, opening the third heating furnace 12 to make the temperature in the carbon-coated reaction chamber reach 600℃ and keep warm, opening the fourth heating furnace 16 to make the temperature in the pre-lithium reaction chamber 17 reach 500℃ and keep warm, the silicon monoxide raw material is vacuum heated in the vacuum reaction chamber 4 for 4h to form steam;

[0114] (2) the steam obtained in step (1) is transported to the deposition reaction chamber 7 by the conveyor 5, and is heated and deposited in the deposition reaction chamber 7 for 2h to obtain block silicon monoxide;

[0115] (3) opening the second valve 8, the block silicon monoxide obtained in step (2) enters the jet mill 9, then closing the second valve 8, the block silicon monoxide is crushed in the jet mill 9 and then enters the sifter 10, the coarse particles enter the jet mill 9 for secondary crushing and then enter the sifter 10, and after sifting, powder silicon monoxide with a particle size of 5μm is obtained;

[0116] (4) opening the third valve 11, the powder silicon monoxide obtained in step (3) enters the fluidized bed coating reaction chamber 13, after closing the third valve 11, nitrogen is introduced into the fluidized bed coating reaction chamber 13 to make the powder silicon monoxide fluidized, and acetylene is introduced for carbon coating to obtain powder particles, the total gas velocity of nitrogen and acetylene is 1m / s, the volume of acetylene accounts for 10% of the total volume of acetylene and nitrogen, the total time of fluidization and carbon coating is 1h, and the tail gas is introduced into the tail gas collector 14;

[0117] (5) opening the fourth valve 15, the powder particles obtained in step (4) enter the pre-lithium reaction chamber 17, lithium hydroxide is vaporized and reacts with the powder particles obtained in step (4) for 1h to obtain silicon monoxide negative electrode material, which enters the product collector 18.

[0118] Example 4

[0119] The present embodiment provides a preparation method of the above preparation device, except that the fluidized bed coating reaction chamber 13 in step (4) is replaced by a fixed bed reactor, i.e. carbon coating is carried out in the fixed bed reactor, and the rest is the same as example 1.

[0120] The silicon monoxide negative electrode material prepared by the preparation method in examples 1-4 is used as a negative electrode material, a ternary nickel-cobalt-manganese lithium acid lithium positive electrode material and a matching electrolyte are selected to assemble a battery, and the electrochemical performance of the assembled battery is determined by using the test method in GB / T24533-2009, including the first discharge specific capacity, the first coulombic efficiency and the capacity retention rate of 100 cycles, and the test results are shown in Table 1.

[0121] Table 1

[0122] Initial discharge specific capacity mAh g -1 ]] First coulomb efficiency % Capacity retention % at 100 cycles Example 1 1580 94 95 Example 2 1510 88 93 Example 3 1480 85 93 Example 4 1200 67 60

[0123] From Table 1, it can be seen that:

[0124] (1) The silicon monoxide negative electrode material is prepared by using the preparation method of the preparation device provided by the application, which has the advantages of short production time, high yield and continuous operation, and the battery assembled by the prepared silicon monoxide negative electrode material has high first discharge specific capacity, high first coulombic efficiency and high capacity retention rate of 100 cycles;

[0125] (2) As can be seen from the comparison between example 1 and example 4, the battery prepared by using the silicon monoxide negative electrode material prepared by the preparation device and the preparation method provided by the application has excellent electrochemical performance; however, in example 4, the coating is not successful because the powder cannot be fluidized and flow in the reactor when the fixed bed is used for coating, and the electrochemical performance of the battery prepared by using the silicon monoxide negative electrode material obtained in example 4 is poor.

[0126] In summary, the preparation device of the silicon monoxide negative electrode material provided by the application is based on high-temperature vacuum evaporation in the vacuum heating assembly and the heating deposition assembly, crushing and screening in the crushing and screening assembly, chemical vapor deposition in the carbon coating heating assembly and gas phase prelithiation in the prelithiation assembly, and a silicon monoxide negative electrode material with excellent performance is prepared. The process system solution for preparing the silicon monoxide negative electrode material is formed by the preparation device. The preparation method realizes the continuous performance of the bulk production, crushing and screening, carbon coating and prelithiation treatment of the silicon monoxide, shortens the preparation period of the silicon negative electrode material, and has the advantages of simple preparation process, strong operability, safety, reliability, environmental friendliness and low cost. The silicon monoxide negative electrode material prepared by the preparation method has the performance advantages of high first coulombic efficiency, high cycle specific capacity and high cycle stability.

[0127] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the application can be easily thought of by those skilled in the art, and all fall within the protection scope and disclosure scope of the application.

Claims

1. An apparatus for preparing silicon suboxide anode material, characterized in that, The preparation device comprises, sequentially connected along a material flow direction, a vacuum heating assembly, a heating deposition assembly, a crushing and screening assembly, a carbon-coating heating assembly, and a pre-lithium assembly. The heating temperature of the vacuum heating assembly is higher than the heating temperature of the heating deposition assembly. The carbon-coating heating assembly comprises a carbon-coating reaction chamber and a third heating furnace arranged outside the periphery of the carbon-coating reaction chamber; the carbon-coating reaction chamber comprises a fluidized bed coating reaction chamber; the fluidized bed coating reaction chamber is a vertical fluidized bed.

2. The preparation device according to claim 1, characterized in that The preparation device further comprises a stock bin arranged before the vacuum heating assembly along a material flow direction.

3. The preparation device according to claim 2, characterized in that A first valve is arranged on a connecting pipeline between the stock bin and the vacuum heating assembly.

4. The preparation device according to claim 2, characterized in that The vacuum heating assembly comprises a vacuum reaction chamber and a first heating furnace arranged outside the periphery of the vacuum reaction chamber.

5. The preparation device according to claim 1, characterized in that The preparation device further comprises a conveyor arranged between the vacuum heating assembly and the heating deposition assembly along a material flow direction.

6. The preparation device according to claim 4, characterized in that The heating deposition assembly comprises a deposition reaction chamber and a second heating furnace arranged outside the periphery of the deposition reaction chamber.

7. The preparation device according to claim 6, characterized in that The heating temperature of the first heating furnace is higher than the heating temperature of the second heating furnace.

8. The preparation device according to claim 6, characterized in that A second valve is arranged on a connecting pipeline between the heating deposition assembly and the crushing and screening assembly.

9. The preparation device of claim 1, wherein, The crushing and screening assembly comprises a crusher and a screener connected to each other; the crusher is connected to the heating deposition assembly, and the screener is connected to the carbon-coating heating assembly.

10. The preparation device according to claim 9, characterized in that The crusher is provided with a crusher outlet, a first inlet, and a second inlet; the screener is provided with a screener inlet, a first outlet, and a second outlet. The crusher outlet is in communication with the screener inlet; the first inlet is in communication with the outlet of the heating deposition assembly; the first outlet is in communication with the inlet of the carbon-coating heating assembly; and the second inlet is in communication with the second outlet.

11. The preparation device of claim 9, wherein The crusher comprises an airflow crusher.

12. The preparation device of claim 1, wherein, A third valve is arranged on a connecting pipeline between the crushing and screening assembly and the carbon-coating heating assembly.

13. The preparation device of claim 1, wherein, The bottom of the fluidized bed coating reaction chamber is provided with a fluidizing gas inlet pipe and a carbon source gas inlet pipe.

14. The preparation device according to claim 13, characterized in that Flow control valves are arranged on the fluidizing gas inlet pipe and the carbon source gas inlet pipe.

15. The preparation device of claim 1, wherein, An exhaust gas collector is connected to the carbon-coating reaction chamber.

16. The preparation device of claim 1, wherein, A fourth valve is arranged on a connecting pipeline between the carbon-coating heating assembly and the pre-lithium assembly.

17. The preparation device of claim 1, wherein, The pre-lithium assembly comprises a pre-lithium reaction chamber and a fourth heating furnace arranged outside the periphery of the pre-lithium reaction chamber.

18. The preparation device of claim 1, wherein, The preparation device further comprises a product collector arranged after the pre-lithium assembly along a material flow direction.

19. A method of making a product using the apparatus of any one of claims 1 to 18, wherein, The preparation method comprises: After the silicon monoxide raw material is vacuum heated in the vacuum heating assembly to form steam, the obtained steam enters the heating deposition assembly to obtain blocky silicon monoxide through heating deposition; after the blocky silicon monoxide enters the crushing and screening assembly to be subjected to at least one crushing and screening treatment, the blocky silicon monoxide enters the carbon-coating heating assembly to be subjected to fluidization treatment and carbon-coating treatment to obtain powder particles; and the obtained powder particles enter the pre-lithium assembly to be subjected to pre-lithium treatment to obtain a silicon monoxide negative electrode material.

20. The method of claim 19, wherein, The preparation method comprises the following steps: (1) opening the first valve, closing the second valve, the third valve and the fourth valve, the silicon monoxide raw material in the silo enters the vacuum reaction chamber, after closing the first valve, the vacuum reaction chamber is subjected to vacuum treatment, the first heating furnace is opened to make the temperature in the vacuum reaction chamber reach the first set temperature and keep warm, the second heating furnace is opened to make the temperature in the deposition reaction chamber reach the second set temperature and keep warm, the third heating furnace is opened to make the temperature in the carbon-coated reaction chamber reach the third set temperature and keep warm, the fourth heating furnace is opened to make the temperature in the pre-lithium reaction chamber reach the fourth set temperature and keep warm, the silicon monoxide raw material is subjected to vacuum heating in the vacuum reaction chamber to form steam; (2) the steam obtained in step (1) is transported to the deposition reaction chamber by the conveyor, and after being heated and deposited in the deposition reaction chamber, blocky silicon monoxide is obtained; (3) opening the second valve, the blocky silicon monoxide obtained in step (2) enters the jet mill, then closing the second valve, the blocky silicon monoxide is subjected to crushing treatment in the jet mill and then enters the sifter, after being screened in the sifter, the coarse particles are subjected to secondary crushing treatment in the jet mill and then enter the sifter, and after screening, powder silicon monoxide with a set particle size is obtained; (4) opening the third valve, the powder silicon monoxide obtained in step (3) enters the fluidized bed coating reaction chamber, after closing the third valve, the fluidized gas is introduced into the fluidized bed coating reaction chamber to make the powder silicon monoxide be subjected to fluidization treatment, and the carbon source gas is introduced to make the powder silicon monoxide be subjected to carbon coating treatment, and then powder particles are obtained, and the tail gas generated is introduced into the tail gas collector; (5) opening the fourth valve, the powder particles obtained in step (4) enter the pre-lithium reaction chamber, and the silicon monoxide negative electrode material obtained after pre-lithium treatment enters the product collector.

21. The method of claim 20, wherein, The vacuum degree in the vacuum reaction chamber after the vacuum treatment is 0.01-100 Pa.

22. The method of claim 20, wherein, The first set temperature in step (1) is 1100-1600℃.

23. The preparation method according to claim 20, characterized in that, The second set temperature in step (1) is 500-900℃.

24. The method of claim 20, wherein, The third set temperature in step (1) is 600-1000℃.

25. The method of claim 20, wherein, The fourth set temperature in step (1) is 500-900℃.

26. The method of claim 20, wherein, The vacuum heating time in step (1) is 4-24 h.

27. The method of claim 20, wherein, The heating and deposition time in step (2) is 2-8 h.

28. The method of claim 20, wherein, The set particle size in step (3) is 1-20 μm.

29. The method of claim 20, wherein, The total time of the fluidization treatment and the carbon coating treatment in step (4) is 0.5-2 h.

30. The method of claim 20, wherein, The fluidized gas includes nitrogen and / or argon.

31. The method of claim 20, wherein, The carbon source gas includes any one or a combination of at least two of methane, ethylene, acetylene or propylene.

32. The method of claim 20, wherein, The carbon source gas accounts for 5-30% of the total volume of the carbon source gas and the fluidized gas.

33. The method of claim 20, wherein the method is carried out at a temperature of about 20°C to about 30°C. The total gas velocity of the fluidized gas and the carbon source gas introduced is 0.1-2 m / s.

34. The method of claim 20, wherein, The pre-lithium treatment time in step (5) is 1-5 h.

35. The method of claim 20, wherein the method is carried out at a temperature of about 20°C to about 30°C. The pre-lithium treatment in step (5) includes vaporizing a lithium source and then performing a lithiation reaction on the surface of the powder particles obtained in step (4).

36. The method of claim 35, wherein the method is performed in a single step. The lithium source includes any one or a combination of at least two of lithium carbonate, lithium hydroxide or lithium oxide.

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