Towards high cycle stability yolk-shell structured silicon/rGO/MWCNT hybrid composites for Li-ion battery negative electrodes

Abstract

Owing to the highest known theoretical specific capacity of 4200 mAhg(-1), low lithiation voltage characteristics and natural abundance, silicon is considered as the most promising negative electrode material for lithium ion batteries which has the potential to replace graphite. Although having striking features, massive volumetric expansions leading to mechanical pulverization and unstable solid electrolyte interphase hinder silicon to be practically exploited as negative electrode material. To address this challenge we design a binder-free and freestanding composite electrode structure which contains embedded silicon yolk-shell particles between graphene/multi walled carbon nanotube skeleton as anode for lithium ion batteries. Electrochemical charge/discharge test results showed that composite anodes exhibited 951 m Ahg(-1) of gravimetric capacity after 500 cycles. This remarkable performance could be ascribed to the complementary effect of yolk-shell particles and conductive structure of graphene/carbon nanotube skeleton.