Tin dioxide nanoparticles impregnated in graphite oxide for improved lithium storage and cyclability in secondary ion batteries

Abstract

SnO2/graphene nanocomposites were prepared from graphite oxide (GTO). Sn2+ precursors were impregnated between graphene layers of GTO and subsequently subjected to thermal treatment to produce nanocomposites consisting of SnO2 and reduced GTO (SnO2/rGTO). When thermally reduced, the pre-aligned nature of graphene layers in GTO produced densely packed and thick graphene stacks, in contrast to graphene layers in the SnO2 nanocomposites (SnO2/rGO) made from thermal reduction of mechanically exfoliated graphene oxide (GO). The surface area and void volume of the SnO2/rGTO nanocomposites (280m2g-1 and 0.27cm3g-1, respectively) were significantly decreased, by comparison with those of the SnO2/rGO nanocomposites (390m2g-1 and 0.39cm3g-1, respectively), which resulted in an enhanced dimensional-stability of SnO2 during the lithium alloying/dealloying processes. As a result, SnO2/rGTO proved to be superior to SnO2/rGO as an anode material in lithium ion batteries from the view-point of both reversible charge-discharge (C-D) capacity and cyclability. The simplification of the nanocomposite preparation process (the removal of mechanical exfoliation) is an additional benefit of using GTO as a template.