Core@shell Sb@Sb2O3 nanoparticles anchored on 3D nitrogen-doped carbon nanosheets as advanced anode materials for Li-ion batteries

Abstract

Antimony (Sb) based materials are regarded as promising anode materials for Li-ion batteries (LIBs) because of the high capacity, appropriate working potential, and earth abundance of antimony. However, the quick capacity decay due to the huge volume expansion during the cycling process seriously hinders its practical applications. Here, a nanocomposite of core@shell Sb@Sb₂O₃ particles anchored on 3D porous nitrogen-doped carbon (3DNC) nanosheets is synthesized by freeze drying and sintering in a reducing atmosphere. Structural characterization shows that the developed Sb@Sb₂O₃/3DNC electrode has a high surface area (839.8 m² g⁻¹) and unique Sb–O–C bonding, both contributing to the excellent electrochemical performance. The initial charge and discharge specific capacities of the Sb@ Sb₂O₃/3DNC anode in LIB tests are 1109 mA h g⁻¹ and 1810 mA h g⁻¹, respectively. Also, it shows a charge capacity of 696.9 mA h g⁻¹ after 500 cycles at 1 A g⁻¹ and 458 mA h g⁻¹ at a current density of 5 A g⁻¹. Moreover, the assembled Sb@Sb₂O₃/3DNC‖LiNi_0.6Co_0.2Mn_0.2O₂ battery exhibits a discharge capacity of more than 100 mA h g⁻¹ after 25 cycles at 100 mA g⁻¹. The synthetic method can be extended to obtain other nanocomposites of metal and carbon materials for high-performance energy storage devices.