Method for preparing nanoscale porous crystal Si through magnesiothermic reduction

The invention discloses a method for preparing nanoscale porous crystal Si through magnesiothermic reduction, which belongs to the technical field of silicon material preparation. The method comprises the following steps of preparing spherical nanoscale SiO2 particles through hydrolysis and condensation of TEOS by taking L-lysine as a catalyst, enabling the prepared nanoscale SiO2 particles and Mg powder to be subjected to ball milling and mixing to obtain a Mg@SiO2 complex, then enabling the Mg@SiO2 complex to be subjected to magnesiothermic reduction reaction, and then acquiring the nanoscale porous crystal Si particles through HCl acid etching, centrifugation and drying. The nano SiO2 material prepared by the method is uniform in particle size and relatively large in specific surface area, and provides convenience for subsequent procedures applied to nano SiO2; the SiO2 is uniformly mixed with Mg powder to form a Mg@SiO2 complex, the diffusion path of Mg steam is shortened, the reaction degree is improved,