Construction of ternary Sn/SnO2/nitrogen-doped carbon superstructures as anodes for advanced lithium-ion batteries

Abstract

Pristine tin (Sn) and tin dioxide (SnO₂) have sparked wide interest owing to their abundant resources and superior theoretical capacity. Nevertheless, the obvious volume expansion effect upon cycling and undesirable conductivity of Sn-based materials lead to undesirable specific capacity. In this work, a nanostructured Sn/SnO₂/nitrogen-doped carbon (NC) superstructure was prepared through a facile electrospray-carbonization strategy. The Sn/SnO₂ nanoparticles (NPs) were uniformly dispersed in a spherical NC matrix, which prevented the volume expansion and aggregation of NPs and facilitated the ion diffusion and charge transfer kinetics. When the optimized Sn/SnO₂/NC superstructures were employed as lithium-ion battery anodes, a remarkable specific capacity of 747.9 mAh·g⁻¹ over 200 cycles at 0.5 A·g⁻¹ and a superior cyclability of 644.1 mAh·g⁻¹ over 1000 cycles at 2 A·g⁻¹ were obtained. This effective synthetic strategy for synthesizing superstructures provides valuable insights for the advancement of lithium-ion batteries.