Preparation and characterization of composite materials obtained by pressure infiltration of aluminum in sintered SiC/kaolin preforms

Microsized Porous SiOx@C Composites Synthesized through Aluminothermic Reduction from Rice Husks and Used as Anode for Lithium-Ion Batteries

“…This process not only requires high temperatures but also has a relatively weak reducing capacity. ,,,− The reaction temperature when Al powder is used as reducing agent for silica in PCRH could decrease to 700 °C, following a relatively strong reducing power. In addition, contrary to Mg powder as reducing agent, the excess Al powder could not react with the obtained Si leading to the loss of Si during reduction. ,, The possible chemical reactions between SiO 2 , Al, and C at 700 °C are shown in reactions and , ,− as follows: Al 2 O 3 , Al 4 C 3 , and unreacted Al are removed by HCl treatment, yielding SiO x @C composites and some SiC. Al melt at 700 °C could not react with C but has a certain permeability that allows Al to pass through the C matrix to react with SiO 2 .…”

“…In addition, contrary to Mg powder as reducing agent, the excess Al powder could not react with the obtained Si leading to the loss of Si during reduction. 27,33,34 The possible chemical reactions between SiO 2 , Al, and C at 700 °C are shown in reactions 1 and 2, 33,35−38 as follows:…”