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

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.