In Situ Synthesis of Tungsten-Doped SnO₂ and Graphene Nanocomposites for High-Performance Anode Materials of Lithium-Ion Batteries

The composite of tungsten-doped SnO 2 and reduced graphene oxide was synthesized through a simple one-pot hydrothermal method. According to the structural characterization of the composite, tungsten ions were doped in the unit cells of tin dioxide rather than simply attaching to the surface. Tungsten-doped SnO 2 was in situ grown on the surface of graphene sheet to form a three-dimensional conductive network that enhanced the electron transportation and lithium-ion diffusion effectively. The issues of SnO 2 agglomeration and volume expansion could be also avoided because the tungsten-doped SnO 2 nanoparticles were homogeneously distributed on a graphene sheet. As a result, the nanocomposite electrodes of tungsten-doped SnO 2 and reduced graphene oxide exhibited an excellent long-term cycling performance. The residual capacity was still as high as 1100 mA h g –1 at 0.1 A g –1 after 100 cycles. It still remained at 776 mA h g –1 after 2000 cycles at the current density of 1A g –1 .