Unified NCNT@rGO bounded porous silicon composite as an anode material for Lithium-ion batteries

Nano/micro silicon particles were achieved by high energy ball milling of silicon mesh powder as a cheap and scalable process and used to make porous silicon by acid etching. Subsequent dispersing of porous silicon with nitrogen-doped carbon nanotubes and graphene oxide followed by filtration and heat treatment gives the composite of unified structures of NCNT@rGO protected porous silicon. The obtained composite was studied as an anode material for Li-ion batteries, and it delivered a high reversible capacity of 862/861 mAh g(-1) at 200 mA g(-1) with 91% of capacity retention. Along with superior rate capability, the prepared composite exhibited 578 and 451 mAh g(-1) discharge capacity at 1,000 and 2,000 mA g(-1) after a long 300 cycles. The enhanced electrochemical performance of the composite electrode can be accredited to the highly conductive and tough matrix of NCNT@rGO blend structures, and porosity in silicon effectively controls the silicon expansion and accommodates the required buffer volume during lithiation/de-lithiation.