Synthesis of curved Si flakes using Mg powder as both the template and reductant and their derivatives for lithium-ion batteries

Abstract

Silicon has been considered as one of the most promising carbon-alternative anode materials for high-energy lithium-ion batteries (LIBs). However, it is still challenging to facilely prepare Si with unique micro-/nano-structures on a large scale. Here, we report a designed procedure for the synthesis of curved Si microflakes. Commercial Mg powder was used as both the active template for SiO₂ coating and reductant to subsequently reduce SiO₂ sheaths into Si by magnesiothermic reaction, for the first time. The as-obtained curved Si flakes could be further tailored. We demonstrated that Sn@carbon nanorods (CRNs) could be formed on the surface of curved Si flakes forming a Si@Sn@CNR composite. When tested as anode materials for LIBs, the as-prepared Si@Sn@CNR composites exhibited highly improved electrochemical performance as compared to pure Si materials.