A system and a method for producing silicon from a SiO.sub.2-containing material that includes solid SiO.sub.2. The method uses a reaction vessel including a first section and a second section in fluid communication with said first section. The method includes: heating the SiO.sub.2-containing material that includes the solid SiO.sub.2 to a SiO.sub.2-containing material that includes liquid SiO.sub.2, at a sufficient temperature to convert the solid SiO.sub.2 into the liquid SiO.sub.2; converting, in the first section, the liquid SiO.sub.2 into gaseous SiO.sub.2 that flows to the second section by reducing the pressure in the reaction vessel to a subatmospheric pressure; and reducing, in the second section, the gaseous SiO.sub.2 into liquid silicon using a reducing gas. The reducing of the pressure is performed over a continuous range of interim pressure(s) sufficient to evaporate contaminants from the SiO.sub.2-containing material, and removing by vacuum, the one or more evaporated gaseous contaminants.

A system and a method for producing silicon from a SiO.sub.2-containing material that includes solid SiO.sub.2. The method uses a reaction vessel including a first section and a second section in fluid communication with said first section. The method includes: heating the SiO.sub.2-containing material that includes the solid SiO.sub.2 to a SiO.sub.2-containing material that includes liquid SiO.sub.2, at a sufficient temperature to convert the solid SiO.sub.2 into the liquid SiO.sub.2; converting, in the first section, the liquid SiO.sub.2 into gaseous SiO.sub.2 that flows to the second section by reducing the pressure in the reaction vessel to a subatmospheric pressure; and reducing, in the second section, the gaseous SiO.sub.2 into liquid silicon using a reducing gas. The reducing of the pressure is performed over a continuous range of interim pressure(s) sufficient to evaporate contaminants from the SiO.sub.2-containing material, and removing by vacuum, the one or more evaporated gaseous contaminants.

A method for etching materials in which organic solvents are added to the etching mixture and combined in a mixing arrangement. When agitated organic materials mix with the etching agent and interact with the underlying material to form a shield around the etched areas that prevents the additional interaction of water with the newly etched areas and enables the etching of silicon oxides (SiOx) but does not oxidize Si. This method leads to milder reactions with less heat generation and avoids the safety hazards associated with conventional etching methods.

A method for etching materials in which organic solvents are added to the etching mixture and combined in a mixing arrangement. When agitated organic materials mix with the etching agent and interact with the underlying material to form a shield around the etched areas that prevents the additional interaction of water with the newly etched areas and enables the etching of silicon oxides (SiOx) but does not oxidize Si. This method leads to milder reactions with less heat generation and avoids the safety hazards associated with conventional etching methods.

Provided are a method of manufacturing an amorphous silicon composite and an apparatus for manufacturing an amorphous silicon composite. The method of manufacturing an amorphous silicon composite, according to an embodiment, may include forming molten silicon by melting a silicon raw material, obtaining an amorphous silicon powder by cooling the molten silicon with a cooling device such that the molten silicon is solidified before being crystallized, obtaining amorphous nano-silicon by performing wet grinding on the amorphous silicon powder, obtaining a first mixture by mixing a first pitch with the amorphous nano-silicon, obtaining a second mixture by coating a second pitch on the first mixture, and obtaining the amorphous silicon composite by performing heat treatment on the second mixture.

Provided are a method of manufacturing an amorphous silicon composite and an apparatus for manufacturing an amorphous silicon composite. The method of manufacturing an amorphous silicon composite, according to an embodiment, may include forming molten silicon by melting a silicon raw material, obtaining an amorphous silicon powder by cooling the molten silicon with a cooling device such that the molten silicon is solidified before being crystallized, obtaining amorphous nano-silicon by performing wet grinding on the amorphous silicon powder, obtaining a first mixture by mixing a first pitch with the amorphous nano-silicon, obtaining a second mixture by coating a second pitch on the first mixture, and obtaining the amorphous silicon composite by performing heat treatment on the second mixture.

A method for preparing an amorphous silicon powder for an anode material of a lithium-ion battery is disclosed. The amorphous silicon powder is prepared by reducing an oxide of silicon, wherein an X-ray diffraction peak of an amorphous silicon material is weak, and the amorphous silicon material is of an amorphous structure. A structural formula of the oxide of silicon is SiO.sub.x, wherein 0<x≤2.The reduction refers to vapor phase reduction, a vapor phase reduction atmosphere is a mixed gas of hydrogen and carbon monoxide, a reduction temperature ranges from 100° C. to 700° C., and a reduction time ranges from 2 h to 72 h.

A method for preparing an amorphous silicon powder for an anode material of a lithium-ion battery is disclosed. The amorphous silicon powder is prepared by reducing an oxide of silicon, wherein an X-ray diffraction peak of an amorphous silicon material is weak, and the amorphous silicon material is of an amorphous structure. A structural formula of the oxide of silicon is SiO.sub.x, wherein 0<x≤2.The reduction refers to vapor phase reduction, a vapor phase reduction atmosphere is a mixed gas of hydrogen and carbon monoxide, a reduction temperature ranges from 100° C. to 700° C., and a reduction time ranges from 2 h to 72 h.

A composite comprising a compound formed using a multistage magnesiothermic reduction reaction, wherein the compound comprises particles comprising silicon and oxygen. Applications of the composite in electrochemical cells are further described.

A composite comprising a compound formed using a multistage magnesiothermic reduction reaction, wherein the compound comprises particles comprising silicon and oxygen. Applications of the composite in electrochemical cells are further described.