Si–CNT/rGO Nanoheterostructures as High‐Performance Lithium‐Ion‐Battery Anodes

A robust and electrochemically stable 3D nanoheterostructure consisting of Si nanoparticles (NPs), carbon nanotubes (CNTs) and reduced graphene oxide (rGO) is developed as an anode material (Si-CNT/rGO) for lithium-ion batteries (LIBs). It integrates the benefits from its three building blocks of Si NPs, CNTs, and rGO; Si NPs offer high capacity, CNTs act as a mechanical, electrically conductive support to connect Si NPs, and highly electrically conductive and flexible rGO provides a robust matrix with enough void space to accommodate the volume changes of Si NPs upon lithiation/delithiation and to simultaneously assure good electric contact. The composite material shows a high reversible capacity of 1665mAhg(-1) with good capacity retention of 88.6% over 500 cycles when cycled at 0.5C, that is, a 0.02% capacity decay per cycle. The high-power capability is demonstrated at 10C (16.2Ag(-1)) where 755mAhg(-1) are delivered, thus indicating promising characteristics of this material for high-performance LIBs.