Rapid preparation device and method of silicon nanowire material

Abstract

The invention provides a rapid preparation device and method of a silicon nanowire material, and belongs to the field of nano material preparation. The preparation device is named as a thermal shock device and comprises a silicon raw material loading system, a drying system, a thermal shock silicon nanowire preparation system and a silicon nanowire collection system. The silicon raw material loading system comprises a carbon substrate bearing rolling rod, silicon slurry stirring and containing equipment, a carbon substrate transition roller and a carbon substrate bearing rolling rod for loading waste silicon powder; the drying system comprises an inert atmosphere infrared high-temperature drying oven and a drying carbon substrate winding bearing rod; the thermal shock preparation silicon nanowire system comprises a rotatable conductive roller, a binding post, a control rod, a sliding rail and a power supply; the collecting system comprises a carbon substrate winding and bearing rod, a silicon nanowire separating device and a silicon nanowire collector. And the whole system is fixedly arranged on an insulating plate. The device disclosed by the invention can be used for rapidly and efficiently preparing the silicon nanowire at low cost, so that the preparation equipment and process of the silicon nanowire are effectively simplified, the efficiency is improved, and the cost is reduced.

Description

Technical Field

[0001] The invention belongs to the field of nano material preparation, and discloses a rapid preparation device and method for silicon nanowire material. Background Art

[0002] Silicon nanowire materials have emerged in the fields of lithium-ion batteries, transistors, optoelectronic materials, semiconductor devices, etc. due to their unique structural advantages. Especially as negative electrode materials for lithium-ion batteries, they can significantly increase the energy density of batteries to more than 400Wh / kg. However, the current preparation methods of silicon nanowires mainly include chemical vapor deposition, laser ablation, thermal evaporation, and metal-assisted chemical etching.

[0003] For example, CN101891145A discloses a method for synthesizing silicon nanowires by gas-liquid-solid, firstly, a thin layer of metal (Au, Fe, Ni, Ga or Al, etc.) with catalytic effect is deposited on a silicon substrate by sputtering or evaporation, then the temperature is raised and heated, and alloy droplets are formed by the eutectic effect of the metal and the silicon substrate. Thereafter, Si source gas (SiH4, Si2H6 or SiCl4, etc.) or solid target thermal evaporation is introduced to allow gas phase silicon to participate in the nucleation and growth of silicon nanowires. CN101892456A discloses a method for preparing silicon nanowires by laser ablation, which method is based on the phase diagram of the eutectic alloy formed by the nanowire components and their catalytic components, and is mixed and configured into a target material in a certain proportion, and then the eutectic temperature is used to adjust the laser irradiation energy density and control the condensation conditions of the material to prepare silicon nanowires; in this method, the laser is used as a heat source, and the target material is heated, melted and evaporated into a gaseous state under the action of laser irradiation. CN101891197A discloses a method for preparing silicon nanowires with the assistance of other substances. The method uses silicon oxide or other substances as raw materials, plasma or direct thermal vapor phase method, and oxide-assisted growth mechanism to prepare silicon nanowire materials. CN107634005A discloses a method for preparing silicon nanowire arrays based on metal-assisted chemical etching technology. The method uses chemical reaction to place a silicon wafer with silver particles deposited in a mixed solution of hydrofluoric acid and hydrogen peroxide to prepare a length-controllable silicon nanowire array. The above-mentioned preparation methods all have the disadvantages of complex preparation process, long time consumption, low efficiency and high cost, and it is difficult to achieve large-scale preparation of silicon nanowires.

[0004] In summary, developing a simple, efficient and rapid device and method for preparing silicon nanowire materials can promote the low-cost preparation and large-scale synthesis of silicon nanowire materials. Summary of the invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a rapid preparation device and method for silicon nanowire materials, the preparation device comprising a silicon raw material loading system, a drying system, a thermal shock preparation system for silicon nanowires, and a silicon nanowire collection system. The preparation device and method are easy to mass-produce industrially, and the product batches are stable.

[0006] To this end, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a rapid preparation device and method for silicon nanowire materials, wherein the preparation device comprises a silicon raw material loading system, a drying system, a thermal shock preparation system for silicon nanowires, and a silicon nanowire collection system.

[0008] The device for rapidly preparing silicon nanowire materials of the present invention loads silicon raw materials on a carbon substrate by stirring silicon powder slurry, and is used for preparing silicon nanowire materials by electrothermal shock. By controlling the conditions of the thermal shock process, the physicochemical properties of silicon nanowires are regulated, and pure silicon nanowire materials are obtained by using a silicon nanowire separation device and method.

[0009] Furthermore, the vacuum inert chamber is provided with a plurality of high temperature resistant rollers to achieve Z-shaped drying;

[0010] Furthermore, the heating and drying device is installed in a vacuum inert chamber with adjustable temperature;

[0011] Further, the heating and drying device includes one or a combination of at least two of infrared drying, electric heating blast, and thermal radiation;

[0012] Furthermore, the winding device includes an adjustable speed motor and a load-bearing rotating roller;

[0013] Furthermore, the thermal shock system for preparing silicon nanowires includes four conductive graphite rollers with adjustable spacing, a terminal post, a bearing post, a slide rail, a motor, and a power supply;

[0014] Furthermore, the distance between the conductive graphite rollers can be adjusted up and down and left and right;

[0015] Furthermore, the bearing column is made of insulating high temperature resistant material, 4 bearing conductive graphite rollers, and the distance between the left and right side columns is adjustable;

[0016] Further, the conductive graphite roller is connected to the terminal post to adjust the distance between the upper and lower graphite rollers;

[0017] Further, the power supply is a constant voltage power supply or a constant current power supply, connected to the terminal;

[0018] Furthermore, the slide rail is fixed on the base, and its slot matches and slides with the insulating bearing column;

[0019] Furthermore, the motor has an adjustable speed to achieve uniform movement and stop of the carbon substrate;

[0020] Further, the silicon nanowire collection system includes a supporting column, a winder, a silicon nanowire separation device, and a silicon nanowire collector;

[0021] Further, the bearing column is an insulating and load-bearing carbon substrate roller;

[0022] Furthermore, the winder is an adjustable speed motor, which drives the carbon substrate roller to wind at a uniform speed;

[0023] Furthermore, the silicon nanowire separation device is one or a combination of at least two of a brush, a scraper, a scraper, and a manipulator;

[0024] Furthermore, the silicon nanowire collector is a container made of any material of glass, plastic, metal, or wood;

[0025] Further, the silicon nanowire preparation system includes an inert gas chamber;

[0026] Furthermore, the inert gas chamber is filled with one or a combination of at least two of vacuum, argon, nitrogen, a hydrogen / argon mixed gas, and carbon dioxide;

[0027] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0028] (1) Fixing the carbon substrate roller on a support column, driving it with a motor, and placing it in a silicon powder slurry containing a solid-liquid ratio of 1% to 50%. Under the action of stirring and ultrasound, the slurry adheres to the carbon substrate to achieve the loading of silicon powder;

[0029] (2) placing a carbon substrate roller loaded with silicon powder on a supporting column and entering a heating drying chamber at a certain rate at a temperature of 40 to 200° C. to evaporate the water for thermal shock preparation of silicon nanowires;

[0030] (3) clamping the carbon substrate loaded with silicon powder between the conductive carbon rollers, adjusting the left and right spacing (2 mm to 300 mm), turning on the power supply to complete the thermal shock process within 0.001 to 1 second, and preparing silicon nanowires;

[0031] (4) Separating the prepared silicon nanowires from the substrate to obtain pure silicon nanowire materials.

[0032] In a second aspect, the present invention provides a silicon nanowire material produced by the production device and method described in the first aspect.

[0033] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0034] (1) The preparation equipment of the present invention prepares silicon nanowire materials in situ by electrothermal shock, and the equipment is simple, easy to operate, fast and efficient. On the one hand, the preparation device and method are easy to realize large-scale production and stable product batch quality; on the other hand, the silicon nanowire materials obtained by the preparation device and method have good aspect ratio and uniformity and low cost;

[0035] (2) The preparation device and method of the present invention obtains silicon nanowire materials, and adjusts and optimizes the aspect ratio, purity and conversion efficiency of the silicon nanowire materials by controlling the silicon powder loading, thermal shock temperature, thermal shock time, atmosphere, voltage and current;

[0036] (3) The present invention can be adapted to prepare silicon nanowire materials from a variety of silicon raw materials, thereby reducing the production cost of silicon nanowire materials from the source and facilitating low-cost large-scale preparation of silicon nanowires. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the structure of the device for synthesizing silicon nanowire materials by electrothermal shock proposed in the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with specific examples, but the present invention is not limited to the following examples.

[0039] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0040] Example 1

[0041] This embodiment provides a rapid preparation device and method for silicon nanowire materials. The preparation device includes a silicon raw material loading system, a drying system, a thermal shock preparation system for silicon nanowires, and a silicon nanowire collection system.

[0042] The silicon raw material loading system includes an interface 2 between the carbon substrate roller and the supporting column, a carbon substrate roller 3, a supporting column 4, a carbon substrate 5, a solution tank with mechanical stirring 6, an intermediate transition roller 7, a loaded silicon powder carbon substrate 8, and a controllable speed motor 9. The movement of the carbon substrate is driven by the controllable speed motor.

[0043] The drying system comprises a vacuum atmosphere chamber 10 , an intermediate transition roller 12 , an electric heating device 11 , and a controllable speed motor 13 .

[0044] The thermal shock system for preparing silicon nanowires comprises an upper conductive graphite roller 16 with adjustable spacing, a lower conductive graphite roller 17, a terminal post 15, a bearing post 14, a slide rail 19, a silicon powder-loaded carbon substrate 18, and a power source 20.

[0045] The silicon nanowire collection system comprises a silicon nanowire carbon substrate 21 , a supporting column 25 , a winding machine 24 , a controllable speed motor 26 , a silicon nanowire separation device 22 , and a silicon nanowire collector 23 .

[0046] The silicon nanowire preparation devices are all installed on a base 1 .

[0047] Example 2

[0048] This embodiment provides a rapid preparation device and method for silicon nanowire materials. The preparation device includes a silicon raw material loading system, a drying system, a thermal shock preparation system for silicon nanowires, and a silicon nanowire collection system.

[0049] The silicon raw material loading system includes an interface 2 between the carbon substrate roller and the supporting column, a carbon substrate roller 3, a supporting column 4, a carbon substrate 5, a solution tank 6 with ultrasonic stirring, an intermediate transition roller 7, a loaded silicon powder carbon substrate 8, and a controllable speed motor 9. The movement of the carbon substrate is driven by the controllable speed motor.

[0050] The drying system comprises an inert atmosphere chamber 10 , an intermediate transition roller 12 , an infrared heating device 11 , and a controllable speed motor 13 .

[0051] The thermal shock system for preparing silicon nanowires includes an upper conductive metal roller 16 with adjustable spacing, a lower conductive metal roller 17, a terminal post 15, a supporting post 14, a slide rail 19, a silicon powder-loaded carbon substrate 18, and a power source 20.

[0052] The silicon nanowire collection system comprises a silicon nanowire carbon substrate 21 , a supporting column 25 , a winding machine 24 , a controllable speed motor 26 , a silicon nanowire separation device 22 , and a silicon nanowire collector 23 .

[0053] The silicon nanowire preparation devices are all installed on a base 1 .

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "an example", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0055] The above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention.

Claims

1. A rapid preparation device and method for silicon nanowire material, characterized in that: The preparation device comprises a silicon raw material loading system, a drying system, a thermal shock preparation system for silicon nanowires and a silicon nanowire collection system.

2. The preparation device according to claim 1, characterized in that: The silicon raw material loading system in step (1) comprises a silicon slurry stirring tank, a carbon substrate roller, a carbon substrate roller supporting column, and a winding device; Preferably, the silicon slurry stirring tank has a middle stop rod; Preferably, the trough containing the silicon slurry is stirred or ultrasonicated to ensure that the silicon powder is evenly loaded on the carbon substrate; Preferably, the winding device comprises a motor with adjustable speed and a bearing column; Preferably, the carbon substrate supporting column is an insulating column fixed on the substrate.

3. The preparation device according to claim 1 or 2, characterized in that: The drying system includes a vacuum inert chamber, a heating and drying device, and a winding device; Preferably, the vacuum inert chamber is provided with a plurality of high temperature resistant rollers to achieve Z-shaped drying; Preferably, the heating and drying device is installed in a vacuum inert chamber with adjustable temperature; Preferably, the heating and drying device includes one or a combination of at least two of infrared drying, electric heating blast, and thermal radiation; Preferably, the winding device comprises an adjustable speed motor and a load-bearing rotating roller.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The thermal shock system for preparing silicon nanowires includes four conductive graphite rollers with adjustable spacing, a terminal post, a bearing post, a slide rail, a motor, and a power supply; Preferably, the distance between the conductive graphite rollers can be adjusted up and down and left and right; Preferably, the bearing column is made of insulating high temperature resistant material, 4 conductive graphite rollers, and the distance between the left and right columns is adjustable; Preferably, the conductive graphite roller is connected to a terminal post to adjust the distance between the upper and lower graphite rollers; Preferably, the power supply is a constant voltage power supply or a constant current power supply, connected to the terminal; Preferably, the slide rail is fixed on the base, and its slot matches and slides with the insulating bearing column; Preferably, the motor has an adjustable rotation speed to achieve uniform movement and stopping of the carbon substrate.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The silicon nanowire collection system includes a supporting column, a winding machine, a silicon nanowire separation device, and a silicon nanowire collector; Preferably, the support column is an insulating and load-bearing carbon substrate roller; Preferably, the winding machine is an adjustable speed motor, which drives the carbon substrate roller to wind at a uniform speed; Preferably, the silicon nanowire separation device is one or a combination of at least two of a brush, a scraper, a scraper, and a manipulator; Preferably, the silicon nanowire collector is a container made of any one of glass, plastic, metal and wood.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The silicon nanowire preparation system includes an inert gas chamber; Preferably, the inert gas chamber is filled with one of vacuum, argon, nitrogen, a hydrogen / argon mixed gas, carbon dioxide, or a combination of at least two of them.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: (1) Fixing the carbon substrate roller on a support column, driving it with a motor, and placing it in a silicon powder slurry containing a solid-liquid ratio of 1% to 50%. Under the action of stirring and ultrasound, the slurry adheres to the carbon substrate to achieve the loading of silicon powder; (2) placing the carbon substrate roller loaded with silicon powder in step (1) on a supporting column and entering a heating drying chamber at a certain rate to evaporate water for thermal shock preparation of silicon nanowires; (3) clamping the carbon substrate loaded with silicon powder obtained in step (2) between the conductive carbon rollers, adjusting the left and right spacing, turning on the power supply to complete the thermal shock process within 0.001 to 1 second, and preparing silicon nanowires; (4) Separating the silicon nanowires prepared in step (3) from the substrate to obtain pure silicon nanowire material.

8. A silicon nanowire material prepared according to the preparation device and method according to any one of claims 1 to 7.

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