Combustion synthesis of silicon by magnesiothermic reduction

A review of magnesiothermic reduction of silica to porous silicon for lithium-ion battery applications and beyond

“…The two steps involved in this synthesis each have lower Gibbs energies which avoided heat accumulation during reduction. 41 By controlling the stoichiometry in the magnesiothermic reduction, varying amounts of Al 2 O 3 remained in the product. Retaining Al 2 O 3 in the nal product reportedly improved the cycle life of the silicon materials aiding stable SEI formation and buffering volume expansion similar to that reported by Liang, et al 63 Since Al 2 O 3 does not contribute to the capacity of the electrode, the specic capacity of the material was reduced.…”

“…38 The Gibbs energy of magnesiothermic reduction is negative for the entire temperature range 0-1000 C and this indicates that the reaction is exergonic. 40,41 The enthalpy of reaction (1) is exothermic and has signicant ramications as discussed below. 41 The melting point of magnesium is 650 C, and the vapour pressure of Mg at 428 C is 1 Pa.…”

“…40,41 The enthalpy of reaction (1) is exothermic and has signicant ramications as discussed below. 41 The melting point of magnesium is 650 C, and the vapour pressure of Mg at 428 C is 1 Pa. This enables solid magnesium and silica to be placed separately in the reaction vessel and the magnesium gas to diffuse to reduce the silica and/or liquid magnesium to ow over the silica.…”

Direct Synthesis of Methyl Chlorosilanes from Pd‐Mg‐SiO2 Substrates Using Mechanochemistry

“…Recently, the process has been commonly used to produce nanoporous silicon structures primarily for applications in lithium-ion batteries as silicon anodes, in solar cells, and optoelectronics. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] More recently, magnesiothermic reduction of silica-based minerals such as forsterite (2MgO•SiO 2 ) was proposed as an alternative to carbothermic reduction at industrial levels to produce metallurgical grade silicon. [43] Magnesio-milling reduction of SiO 2 is an alternative method to produce elemental silicon.…”

Crystallisation Behaviour of Pharmaceutical Compounds Confined within Mesoporous Silicon

“…The magnesia (MgO) can be easily removed afterwards with HCl, leaving behind a silicon replica with higher surface area than the starting template. The exothermic nature of the reduction reaction allows for utilisation of the heat produced, aiding the process further and lowering the cost of the reaction [101].…”