Silicon Nanowire-Graphite Composites As High Energy Anode Materials for Lithium Ion Batteries

摘要

Silicon is one of the most promising candidates to replace commercial graphite anodes in the next generation of lithium-ion batteries. Although numerous efforts have been devoted to improve the electrochemical performance of the Si based anodes, scalable synthesis of such materials and retaining good cycling stability in high loading electrode remain unaddressed. In pursuit of this goal, we propose a simple and scalable approach to synthesize a novel architecture containing silicon nanowires (SiNWs) grown on carbon powder (graphite, graphene, carbon black). SiNWs are grown from gold nanoparticle catalysts deposited on carbon and from the thermal decomposition of an organosilane oil, diphenylsilane, at 430°C. The SiNWs show thin, homogeneous diameters and a high aspect ratio (the left figure shows a typical SEM image). Composites including up to 70wt% of Si on carbon black and 40wt% Si on graphite are obtained at the gram scale within 2 hours.