Facile approach to an advanced nanoporous silicon/carbon composite anode material for lithium ion batteries

Abstract

A new kind of nanoporous silicon/carbon composite with excellent electrochemical performance was prepared via a mechanochemical reaction between SiCl₄ and Li₁₃Si₄ under ball milling. The whole process is mild and simple, using no corrosive acid. In particular, this method is suitable for large-scale synthesis of nanoporous silicon based composite for a potential anode material of lithium ion batteries. Different structures of silicon and carbon coating approaches were investigated. Compared with nano-Si/SP/C-D and np-Si/SP/C-S, the np-Si/SP/C-D exhibited a considerably high initial capacity of 1413.2 mAh g⁻¹ and an excellent cycling stability with 91.1% capacity retention against at 2nd cycle after 100 cycles at a current density of 100 mA g⁻¹. The superior electrochemical performance is attributed to the open nanoporous structure, which can accommodate the volume expansion, and the excellent electronic and ionic conductivity of a thin carbon layer.