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 categories (1) the fabrication of nanostructured materials and (2) the development of composites with condictuve materials in order to overcome their practical limitations in commercial use. Here, the synthesis, characterizarion, 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.