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

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.