Mesoporous Nano-Si Anode for Li-ion Batteries Produced by Magnesio-Mechanochemical Reduction of Amorphous SiO2

The synthesis of nano-sized Si with various microstructures has been studied intensively to produce anode materials for Li-rechargeable batteries. Methods such as chemical/physical vapor deposition (CVD/PVD) and wet-chemical processes are currently used to produce nano-sized Si; however, the complicated synthesis procedures and low production yields are critical problems that hinder commercialization. We present a method for producing large quantities of mesoporous nano-sized Si through the reduction of amorphous SiO2 with Mg metal, by using a high-energy mechanical milling process (i.e., magnesio-mechanochemical processing) for 1 h. A mesoporous nano-sized Si electrode shows excellent electrochemical performance as an anode for Li-ion batteries, achieving a capacity greater than 1600 mAhg(-1) over 30 cycles.