Enhanced performance of S-doped Sb/Sb2O3/CNT/GNR nanocomposite as anode material in lithium-ion batteries

Abstract

Antimony-based materials are been investigated as a reliable and high capacity anode to substitute graphite in lithium-ion batteries (LIB). Nevertheless, the considerable volumetric variations that lead to electrode pulverization require new strategies to overcome capacity fading and improved cyclability. Herein, we report the one-step hydrothermal synthesis and simultaneous sulfur-doping of Sb/Sb2O3 nanoparticles and 3D carbon network composed of carbon nanotubes and graphene nanoribbons (CNT/GNR), to produce uniformly anchored nanocomposite (S–Sb/Sb2O3/CNT/GNR). This nanocomposite displays a reversible specific capacity as high as 619 mAh g−1 after 100 cycles at 50 mA g−1 and excellent rate performance of 328 mAh g−1 at 2000 mA g−1. After 100 cycles, S–Sb/Sb2O3/CNT/GNR electrode still retains about 71% of its reversible initial capacity, compared to the 39% obtained using Sb/Sb2O3/CNT/GNR. The superior electrochemical performance of the S-doped electrode is attributed to the improvement in the chemical stability of the carbon matrix, as well as the morphological changes brought out by S-doping onto the inorganic nanoparticles that manifest as an increase in the Li-ion diffusion, low charge transfer resistance and superior structure stability upon charge/discharge cycling. The proposed synthetic strategy combines the advantages of S-doping, large surface area carbon matrices, and large capacity Sb-based materials towards stable and high-performance anodes for LIB.