Controlled Synthesis of Hollow Si-C Microspheres and its Potential as an Anode Material in Lithium-Ion Batteries

Abstract

Hollow structure has great potential in lithium-ion batteries, especially in Si-based anode materials. Unlike the usual templating process, here, we report a template-free synthetic strategy to build hollow microspheres of Si-C hybrid materials, which combines an in-situ polymerization process to form precursor and magnesiothermic reduction towards the inner cavity. For hollow Si-C microspheres, the void space in the core could accommodate the volume expansion of Si species and the carbon matrix improves the electrical conductivity. As a result, the hollow Si-C microspheres exhibit improved cycling performance (768.7 mAh g -1 after 100 cycles at 0.84 A g -1 ) and good rate capability (497.1 mAh g -1 at 8.4 A g -1 ) when used as an anode material in lithium-ion batteries.

Keywords: template-free, hollow microspheres, Electrical conductivity, cycling stability, rate capability