Molten Salt-assisted Magnesiothermic Reduction Synthesis of Spherical Si Hollow Structure as Promising Anode Materials of Lithium Ion Batteries

摘要

To solve the critical issue of the poor cycling stability caused by large volume expansion of Si-based anodes during Li lithiation/delithiation processes, spherical Si hollow nanostructures are prepared based on Kirkendall effect via a simple molten salt-assisted magnesiothermic reduction technique. The hollow structure of silicon provides additional internal space for the volume expansion of silicon. The novel hollow Si nanostructure shows good electrochemical performance as Li-ion battery anodes. After 50 cycles, it can provide 1302 mAh.g(-1) capacity with current density of 0.2A.g(-1). The material has a unique hollow structure that allows the expansion of silicon during the lithium process, providing better cycle life and rate capability than direct reduction of bulk silicon.