In situ preparation of uniform and ultrafine SnO2 nanocrystals anchored within a mesoporous carbon network as advanced anode materials

Abstract

The creation of a cooperative effect between zero-dimensional (0D) SnO₂ particles and carbonaceous materials with space-confined structures has shown great potential in achieving advanced lithium-ion battery anodes (LIBs), but is full of challenges. Herein, we report a novel and green approach for the preparation of uniform SnO₂ nanocrystals anchored within a continuous mesoporous carbon network. For the first time, the formation of SnO₂ nanocrystals and in situ carbon-coating were achieved simultaneously through the ion exchange and hydrothermal method (IEHM), and the subsequent calcination further endows the composites with a robust 3D-interconnected porous structure. The resulting product consists of SnO₂ nanocrystals with a uniform size (2.2–3.8 nm) and continuous mesoporous carbon network, which exhibits a large surface area (257 m² g⁻¹) and a high content of SnO₂ (∼70 wt%). As a result, the as-prepared SnO₂/C nanocomposites showed a high reversible capacity of 1024.6 mA h g⁻¹ at 200 mA g⁻¹ even after 300 cycles as an anode material for LIBs. Moreover, the facile preparation of uniform SnO₂ nanocrystals by the IEHM would be helpful in promoting nanostructure engineering of other metal oxide materials.