Solar synthesized tin oxide nanoparticles dispersed on graphene wrapped carbon nanotubes as a Li ion battery anode material with improved stability

Employing high theoretical capacity SnO2 as an anode material for Li ion batteries (LIBs) is still a challenge because of its huge volume change upon lithiation/de-lithiation, leading to instability and a low cycle life of the cell. Herein we report graphene wrapped carbon nanotubes (gC), a one-dimensional monohybrid of multiwalled carbon nanotubes and graphene sheets, which support SnO2 nanoparticles to act as a stable LIB anode. An eco-friendly, solar energy mediated reduction process, instead of hazardous wet chemical methods, was used to decorate SnO2 over the gC support material. The wrinkled surface of gC, with a higher available surface area and favorable Li transfer channels, is explored as a functional preventive measure against the volume change of the metal oxide nanoparticles. This well-connected gC structure with high conductivity also accounts for the semiconducting nature of SnO2, and exhibits less resistance with a highly stable performance, thereby presenting SnO2/gC as a potential anode material for LIBs.