Direct growth of SnO2 nanorods on graphene as high capacity anode materials for lithium ion batteries

Abstract

SnO₂ nanorods/graphene nanosheets (GNSs) nanocomposites have been synthesized through a simple ultrasonic combined hydrothermal process, and the formation mechanism of the nanocomposites has been proposed. According to FESEM and TEM analysis, SnO₂ nanorods are directly grown and densely distributed on GNSs matrix in such a way that the structure of obtained nanocomposites is analogous to an array structure. The as-prepared nanocomposites exhibit a significantly improved lithium-storage capacity, good cycling stability and high rate capability, e.g. the reversible capacity is kept as high as 1107 mA h g⁻¹ within 100 cycles at a current density of 200 mA g⁻¹, retaining 96.2% of the initial value. The high performance can be ascribed to the unique structure of SnO₂ nanorods/GNSs and the synergic effects of GNSs and SnO₂ nanorods, in which the direct growth of SnO₂ nanorods on GNSs can reduce the stacking of GNSs, provide more reaction sites and facilitate the rapid diffusion of electrons.