Fabrication of Hollow Core-Shell Type Si/C Nanocomposites by a Simple Process

Abstract

We have successfully fabricated hollow core-shell type Si/C nanocomposites using a simple process. Si powder was grinded to form Si nanoparticles, mixed with sucrose as a carbon source and ammonium chloride as an expansion agent, and finally annealed in Ar atmosphere. During the annealing, carbon hollow spheres encapsulating Si nanoparticles were spontaneously fabricated through dehydrogenation reaction of the sucrose to form carbon balloons and the balloon expansion by ammonium gas generated during ammonium chloride decomposition. Volume of the empty spaces in the core-shell structure can be controlled by the rising rate in the annealing temperature. This method is suitable for industrial production of hollow Si/C nanocomposites because of its simplicity.

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“…Wakabayashi et al . successfully fabricated hollow core–shell type Si/C nanocomposites using a simple sugar-blowing technique.…”

“…In order to improve the electrochemical performance, a lot of work has been focused on solving the volume expansion and structuring stable interface, such as the electrolyte solution, 18−20 binders, 21−23 structure design. 24−26 Wakabayashi et al 27 successfully fabricated hollow core− shell type Si/C nanocomposites using a simple sugar-blowing technique. The decomposition of the ammonium chloride produces voids between the silicon and carbon layers to accommodate volume expansion.…”