Silicon powder (including micron and nanometer scale) has a wide range of applications in various fields due to its high chemical activity, large specific surface area, and semiconductor properties. For example:

1. Electronics and Semiconductor Industry
Integrated circuits and chips：High purity silicon powder (above 99.999%) is a raw material for manufacturing monocrystalline silicon and polycrystalline silicon, used in semiconductor devices, CPUs, GPUs, and other chips.
Photovoltaic industry：The silicon wafer of solar cells is processed from silicon powder (such as slicing silicon ingots grown by CVD method).
Electronic packaging materials：Nano silicon powder is used for conductive adhesives and thermal fillers to enhance the heat dissipation and conductivity of electronic components.

2. New energy and batteries

Negative electrode material for lithium-ion batteries：Nano silicon powder replaces traditional graphite negative electrode, with a theoretical capacity (4200 mAh/g) far exceeding graphite (372 mAh/g), but the expansion problem needs to be solved (such as using silicon carbon composite materials).
Solid state battery：Silicon powder is combined with solid electrolyte to improve energy density and cycling stability.

So what are the production methods for silicon powder? In fact, there are various methods for preparing silicon powder, and different processes are selected according to purity, particle size, and application requirements. The following are common preparation methods:

1. Mechanical crushing method, its principle is to process block shaped silicon materials into powder through physical crushing, ball milling, or air flow crushing.
Process: The first step is coarse crushing: using a jaw crusher to crush the silicon blocks to the millimeter level. Next, fine grinding: using a ball mill or vibration mill, adding inert gas (such as nitrogen) to prevent oxidation. Then grading: Separate silicon powder of different particle sizes through airflow or sieving.

Its characteristic is low cost and suitable for large-scale production. However, the particle size distribution is wide (in micrometers), which may introduce impurities.

2. Chemical vapor deposition (CVD) method, which works by decomposing silane (SiH ₄) or chlorosilane (such as SiCl ₄) at high temperatures to produce silicon particles.

Reaction equation:
SiH4ΔSi+2H2
SiCl4+2H2→Si+4HClSiCl4+2H2→Si+4HCl

Its process: Firstly, a silicon source gas is introduced into the reactor and heated to 800-1200 ℃. Then adjust the particle size by controlling the temperature, gas flow rate, and pressure.

Its characteristic is that it can obtain high purity (over 99%) and nanoscale particle size. However, the cost is high and it can be used in high-end fields such as electronics and photovoltaics.

3. Metal reduction method, its principle is to reduce silicon dioxide (SiO ₂) with active metals such as magnesium and aluminum.

Reaction equation (magnesium thermal reduction):
SiO2+2Mg→Si+2MgO

Preparation process: First, mix SiO ₂ and magnesium powder, and react at high temperature (650-800 ℃).
Next, acid washing (HCl) is used to remove the by-product MgO.

Its characteristic is low cost, but the purity is affected by the raw materials. Further purification is required (such as acid washing, flotation)

4. Electrolysis method, its principle is to electrolyze molten silicate or SiO ₂ and precipitate silicon at the cathode.

Preparation process: SiO ₂ is used as raw material to react with carbon anode at high temperature (>1400 ℃) to generate Si.

The cathode collects silicon and crushes it into powder.

Its characteristics are high energy consumption and high purity (solar grade). Mainly used for producing polycrystalline silicon and processing it into powder.

The above are the main preparation methods of silicon powder, but there are also other preparation methods. SAT NANO is a best silicon powder supplier in China, we use the Chemical vapor deposition (CVD) method to produce the silicon nanopowder 50nm, 100nm. If you have any enquiry, please feel free to contact us at admin@satnano.com