Three-Dimensional Graphene/Single-Walled Carbon Nanotube Aerogel Anchored with SnO₂ Nanoparticles for High...

A unique 3D graphene-single walled carbon nanotube (G-SWNT) aerogel anchored with SnO₂ nanoparticles (SnO₂@G-SWCNT) is fabricated by the hydrothermal self-assembly process. The influences of mass ratio of SWCNT to graphene on structure and electrochemical properties of SnO₂@G-SWCNT are investigated systematically. The SnO₂@G-SWCNT composites show excellent electrochemical performance in Li-ion batteries; for instance, at a current density of 100 mA g^-1, a specific capacity of 758 mAh g^-1 was obtained for the SnO₂@G-SWCNT with 50% SWCNT in G-SWCNT and the Coulombic efficiency is close to 100% after 200 cycles; even at current density of 1 A g^-1, it can still maintain a stable specific capacity of 537 mAh g^-1 after 300 cycles. It is believed that the 3D G-SWNT architecture provides a flexible conductive matrix for loading the SnO₂, facilitating the electronic and ionic transportation and mitigating the volume variation of the SnO₂ during lithiation/delithiation. This work also provides a facile and reasonable strategy to solve the pulverization and agglomeration problem of other transition metal oxides as electrode materials.