Ultrafine SnO2 Nanoparticles Decorated on N‑Doped Highly Structurally Connected Carbon Nanospheres as Anode Materials for High-Performance Sodium-Ion Batteries

Although SnO2 nanoparticles (NPs) can provide high specific capacities for sodium-ion batteries (SIBs), they are susceptible to rapid deterioration due to SnO2 NP aggregation during charge−discharge cycles. Herein, we report a simple hydrothermal method to prepare SnO2 NPs decorated on highly structurally connected carbon nanospheres (HS-CCNs) without or with nitrogen doping. SnO2/N-HS-CCN functioned admirably as an anode material for SIBs, with a reversible capacity of 294 mA h g-1 after 150 cycles at 0.1 A g−1, which is significantly higher than that in previous findings. In addition, the integration of the synergistic effects of SnO2 and N-HS-CCN resulted in largely improved electrochemical behaviors compared with HS-CCN (undoped material), non-dispersed SnO2, and pure N-HS-CCN. This work highlights the role of nitrogen-doped carbon materials in effectively bridging nano-SnO2 particles with high electron mobility, thus offering high capacity in SIBs from low to medium−high current densities.