A Benign Sol-Gel Route Towards Porous Carbon Coated Sb Nanoparticles: A High-Performance Li-Ion Batteries Anode

Abstract

Rechargeable batteries have wide applications ranging from portable electronics to hybrid electric vehicles owing to an incessant demand for improved capacity and longer lifetime. Metal-based anodes (Sb, Sn, Si, Ge, etc.) can offer high specific capacity albeit with rapid fade due to inherent volume expansion associated with the active phase impedes their commercialization and rapid growth. In the present work, a novel polymer-derived porous carbon coated antimony nanoparticles (Sb@C) based core-shell architecture is proposed for Li-ion batteries anode, wherein a thin conductive carbon shell over Sb nanoparticles (SbNPs) is developed using polymeric diol-aldehyde reactions via a sol-gel route. The core-shell architecture of Sb@C affords a carbon coating act as a buffer and prevents the structural disintegration of SbNPs during Li-ion alloying/de-alloying reactions while improving the rate capability and capacity fade. The structure and morphology of the as-synthesized Sb@C core/shell architecture were studied by XRD, FESEM, and TEM analyses confirmed the formation of thin carbon coating (~100 nm) on to the SbNPs. Preliminary electrochemical results demonstrate that Sb@C anode can deliver a discharge and charge capacity of ~730 mAhg-1 and ~490 mAhg-1 respectively, at a constant current density of ~100 mAg-1 at first cycle. Electrochemical impedance spectroscopy (EIS) results indicate that Sb@C shows lower charge transfer rate (Rct) and improved Li-ion storage performance than the bare SbNPs. Figure 1