Nanoporous silicon prepared through air-oxidation demagnesiation of Mg2Si and properties of its lithium ion batteries

Abstract

Nanoporous silicon has been prepared through the air-oxidation demagnesiation of Mg₂Si at 600 °C for 10 hours (Mg₂Si + O₂ → Si + MgO), followed by HCl washing. Mg₂Si was prepared from 200 mesh commercial Si at 500 °C for 5 h in an autoclave. The as-prepared Si exhibits a reversible capacity of 1000 mA h g⁻¹ at 36 A g⁻¹ and ∼1200 mA h g⁻¹ at 1.8 A g⁻¹ over 400 cycles.