Facile synthesis of Si/NiSi2/C composite derived from metal-organic frameworks for high-performance lithium-ion battery anode

Abstract

Abstract The electrochemical performance of silicon (Si) anode can be improved by transition metal silicide materials because of their excellent electronic conductivity. However, the synthesis of transition metal silicide with controllable nanostructure remains a challenge. Herein, the porous Si/NiSi2/C nanoparticles were synthesized successfully by magnesiothermic co-reduction of silica-coated metal-organic frameworks (MOFs). The MOFs is used as a sacrificial template because of its controllable size and morphology. The as-prepared Si/NiSi2 was uniformly embedded in amorphous carbon materials derived from MOFs. The NiSi2 and carbon can act as a buffer matrix and facilitate the electronic transmission of Si/NiSi2/C. The nanometer size and porous structure of Si/NiSi2/C can accommodate volume expansion during the cycling process. As a result, the as-prepared Si/NiSi2/C electrode delivered a specific capacity of 1243.6 mAh g−1 after 200 cycles at a current density of 1 A g−1. This facile strategy provides the possibility to develop transition metal silicide materials from MOFs for high-performance Si-based anode.