Wednesday, 4 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
Silicon (Si) is considered as next-generation material of the anode because it is rich in nature resource and its high theoretical capacity (4200 mAh/g), which is ten times higher than of commercial graphite anode (372 mAh/g). However, Si suffers a large volume expansion (approximately 400 %) during cycling process. As a result, it induces pulverization of silicon and causes to rapid capacity fading. This study describes controlled fabrication of one-dimensional silicon nanowires (SiNW) cocooned in graphene-like carbon sheath (SiNW@V@GS) for the improved electrochemical performance of Si anode. The specific new advances demonstrated are included in this work. First, the design of the one-dimensional morphology (SiNW@V@GS) for highly conductive network with Si core for high capacity, graphitic carbon sheath for better electrical conductivity and void space for compensation of large volume expansion during the cycling process. Second, we controlled void space between Si core and graphitic carbon sheath by adjusting oxidation time of Si core during CVD process and enabled electrode fabrication with high capacity and stable cycling performance. Finally, we developed facile and scalable synthesis of the prepared SiNW@V@GS materials by using the SiO2 template through successive CVD growth and chemical vigorous etching process.