Reduction-free synthesis of carbon-encapsulated SnO2 nanowires and their superiority in electrochemical performance

Recent pervasive trends in research into metal oxides as anode materials basically fall into two categoriess-(1) the fabrication of nanostructured materials and (2) the development of composites with conductive materials-in order to overcome their practical limitations in commercial use. Here, the synthesis, characterization, and electrochemical properties of C (carbon)-encapsulated SnO2 nanowires have been carefully investigated in an effort to synergistically enhance the anodic properties. The simple evaporation of malic acid (C4H6O5) was sufficient to form an amorphous C phase on the surface of the SnO2 nanowires at low temperature, leading to the further enhancement of the electrochemical performance. The additional C phase could introduce a higher reversible capacity and an improved initial Coulombic efficiency compared to SnO2 nanowires. It is believed that the conductive C phase could provide more electron migration routes between active materials, as well as effectively reduce the capacity loss due to large-volume variation in the metal phase.