Chestnut-like SnO₂/C nanocomposites with enhanced lithium ion storage properties

Highlights: • Chestnut-like SnO₂ nanoparticles are synthesized by oxidizing Sn nanoparticles in glucose solution. • Nanoscale Kirkendall effect and oriented growth are supposed to contribute to the formation of chestnut-like structure. • Chestnut-like SnO₂/C exhibits largely enhanced cycling stability. • Limited volume expansion and excellent mechanical robustness facilitate the enhanced cycling stability. Chestnut-like SnO₂ and SnO₂/C nanocomposites with hierarchical structures are synthesized by hydrothermally oxidizing Sn nanoparticles in glucose solution. Structural characterizations using SEM and TEM reveal that the SnO₂ nanoparticles are composed of numerous, randomly arranged SnO₂ nanosheets with hollow cores. Owing to the short electron and ion diffusion distances and transformation strain accommodation mechanism of this structure the new SnO₂/C nanocomposites exhibit enhanced lithium ion storage properties with a capacity of ~930 mAh g⁻¹ and capacity retention of about 96% after 100 cycles at 0.1 C. An in situ TEM study of the electrochemically driven lithiation/delithiation of SnO₂/C nanocomposites reveals that their enhanced cycling stability is mainly facilitated by the limited volume expansion and excellent mechanical robustness of the hollow chestnuts.